Cooling Fans Not Working

[ccurzio]

Hey all.

So earlier today I had mentioned that I was attempting to wire in DPNW's "Wings-B-Cool" cooling fan modification kit. Aside from being a pretty huge pain thanks to having issues with a missed wire causing the car not to start, the remaining problem I am having is that my cooling fans no longer work at all.

Is anyone familiar with this kit?

http://www.delorean-parts.com/Merchant2/merchant.mvc?Screen=PROD&Store_Code=DPNW&Product_Code=K4003DP&Category_Code=9475

I sent Toby an email a little while ago, but I'm still trying to run down the problem on my own. I need some help with this one. :(

To make absolutely sure I am not dealing with any backed-out relay connections, I pulled all of the wires from both sockets and connected them directly to the appropriate terminals on the relays. Still no go.

[EdR5150]

How did you test the fans? Did you get the car warm enough? Did you try jumping the otterstat? How about when you turn the AC on?

[ccurzio]

I tested by both running the AC and letting the temperature get up to (and past) 220.

The fans worked fine up until this morning before I attempted the wiring modification. The otterstat is fine.

[DMCMW Dave]

I had a variation of that mod on my car for a long time. The instructions are pretty clear, but there is some ambiguity as to which way you are looking at the pins on the sockets. Make sure you aren't looking at the mating side when they show the wire side (or the opposite, I have not seen the instructions for years).

Rather than testing the circuit by overheating the engine :shock:, just put a jumper across the otterstat connectors.

[EdR5150]

The fans worked fine up until this morning before I attempted the wiring modification. The otterstat is fine.

Sounds like a loose connection, a break in the wiring, or incorrect wiring somewhere. Got a test light? Check out the Cooling Fan Schematic, find a good ground, then start testing.

http://dmctalk.org/showthread.php?40-All-Wiring-Schematics

I've had my fans go out due to incorrect fan fail socket jumpering, and on another occasion with a bad breaker.

[ccurzio]

I had a variation of that mod on my car for a long time. The instructions are pretty clear, but there is some ambiguity as to which way you are looking at the pins on the sockets. Make sure you aren't looking at the mating side when they show the wire side (or the opposite, I have not seen the instructions for years).

Rather than testing the circuit by overheating the engine :shock:, just put a jumper across the otterstat connectors.

I always wired everything based on the one vertical pin (#30) being at the top. Based on the instructions, everything is wired correctly since all of the existing wires were in the correct described places.

[DMCMW Dave]

This modification requires you to pull the pins out of the sockets and move them around. At that point the original schematic is useless.

To me the biggest problem with this mod is that if someone comes along later and tries to put the normal fan jumper, a fan controller, or even a blue fan fail module in the socket, Bad Things will happen. When you are done please be sure to put a large label somewhere that explains what you did.

[ccurzio]

This modification requires you to pull the pins out of the sockets and move them around. At that point the original schematic is useless.

No, I get that. What I'm saying is, the instructions detailed quite well where the wires were in the original setup, at least the ones that needed moving. Since all of the descriptions of those wires were correct, I was clearly looking at the correct orientation for the rewire.

Where's the otterstat located so I can jump it? Will that test work without the engine running?

[DMCMW Dave]

No, I get that. What I'm saying is, the instructions detailed quite well where the wires were in the original setup, at least the ones that needed moving. Since all of the descriptions of those wires were correct, I was clearly looking at the correct orientation for the rewire.

Where's the otterstat located so I can jump it? Will that test work without the engine running?

In the coolant pipe just to the left (driver side) of the engine usually facing down. Disconnect the two terminals and jumper them together. The key needs to be on for the fans to run. Engine can be off.

There are some diodes in the circuit that may be damage if a gross wiring error has occurred (see the above-referenced circuit diagram). They are in the large wire loom in the electrical compartment. If the diode(s) open up the fans will not turn on.

[Bitsyncmaster]

Those diodes may have a bad connection after moving the harness around with the install. Find those diodes (in the harness at the far right side of the relay compartment). Unplug and plug back in one connection at a time on those diodes.

[ccurzio]

Found (and jumped) the otterstat. Thanks for the tip, Dave. I knew it was down there somewhere but I couldn't remember exactly where. (And the manual diagrams didn't help a whole lot.)

Still no go with the otterstat wires jumped together.

I also went ahead and tore everything back down for the fourth time and checked all connections, then put everything back together. Still nothing.


To me the biggest problem with this mod is that if someone comes along later and tries to put the normal fan jumper, a fan controller, or even a blue fan fail module in the socket, Bad Things will happen. When you are done please be sure to put a large label somewhere that explains what you did.

I agree. I don't plan on ever selling the car, but even for my own reference this is smart.

[Jonathan]

Wasn't Wings B Cool what they called the auto bleeder kit?

[ccurzio]

Wasn't Wings B Cool what they called the auto bleeder kit?

There's a series of Wings-B-Cool products, one of which is the bleeder kit.

[DMCMW Dave]

Try feeding 12V to the two lines, one at a time, (formerly on the left and right pins of the blue socket) that go directly to the fans. That will at least prove the fans work and that those two lines are in the correct place.

[ccurzio]

Those diodes may have a bad connection after moving the harness around with the install. Find those diodes (in the harness at the far right side of the relay compartment). Unplug and plug back in one connection at a time on those diodes.

I didn't fuss with anything that far over to the right, but I went ahead and found those diodes anyway and secured the connections. No change.


Try feeding 12V to the two lines, one at a time, (formerly on the left and right pins of the blue socket) that go directly to the fans. That will at least prove the fans work and that those two lines are in the correct place.

Grabbed 12v off the circuit breaker and connected it straight into those lines, one at a time. Each fan came right on as soon as power was fed to it.

Another interesting tidbit: I've noticed that with everything hooked up, any time I turn power back on to the car both of these relays click.

[DMCMW Dave]

Another interesting tidbit: I've noticed that with everything hooked up, any time I turn power back on to the car both of these relays click.

That's not good. You must somehow have the trigger (coil) lines on the relays connected to the BATT source. If that is the case, the lines from the diodes are probably trying to feed the fans through the relays (this would quickly burn out the diodes, as they are only rated at an amp or two and the fans pull close to 15 amps EACH on startup). Test the diodes with your ohm meter, if I'm right they will read wide open both directions.

I'm guessing you have the a side pin and the one single pin reversed in your wiring. Take some pictures of the wiring from underneath the sockets, or call out the color codes and pin locations of the wiring.

[ccurzio]

Socket 1 (Fan Fail Module Socket)
30: Black/Green
86: Red (Tapped to 86 on Socket 2)
87A: Black, Black (Two wires on one terminal)
85: Black (Tapped to Ground)
87: Black/Orange

Socket 2 (Fan Relay Socket)
30: Black/Green
86: Black/Orange
87A: Black
85: Black, Black (Two wires on one terminal)
87: Brown/Orange


Test the diodes with your ohm meter, if I'm right they will read wide open both directions.

One had continuity through it, the other did not.

[Bitsyncmaster]

FYI:

Pin 85 is always the relay control circuit "ground" pin on ISO relays. The pin opposite of pin 85 is the control signal. That's how I always keep from swapping those wires which is easy to do looking at the top when the schematic shows it looking at the bottom. The other three (power switching) pins don't get swapped because one pin is rotated and it's the same looking at the top or bottom.

The reason pin 85 has to be the control ground even though a normal relay will work with the control voltages swapped, is that some relays have suppressors built into them. Most suppressors are resistors but some can be diodes.

[ccurzio]

One had continuity through it, the other did not.

I take that back... I removed both diodes from the car and tested each individually with the meter. Neither had continuity from one side to the other.

[DMCMW Dave]

Check for sure, but I'm guessing you have the black (brown)/oranges (86 and 87) swapped around. I don't recall the specifics but my recollection is that the schematic colors don't match the wire colors, and that they use the orange trace for different purposes.

You may need to trace the wires to their source. This is much different from stock, so everyone else ignore these connections. Analyze what you are trying to do:

The solid brown should be going to the breaker, and the breaker should be feeding the two 87s. This is the power source for the relays that ultimately powers the fans.

The two 30s should be feeding the two fans respectively when the relay is engaged. (Black/Green?)

The 86s should be the trigger wiring coming from the two diodes. If that traces back to the circuit breaker that's your problem, this would energize the relays all the time.

The 85s should be ground (relay coil ground)

The two 87a should be ground (this grounds the motors when off)

If you have fed the fans from the diode circuit, as I said before, you have probably smoked the diodes.


PS - do you have a real name?



Socket 1 (Fan Fail Module Socket)
30: Black/Green
86: Red (Tapped to 86 on Socket 2)
87A: Black, Black (Two wires on one terminal)
85: Black (Tapped to Ground)
87: Black/Orange

Socket 2 (Fan Relay Socket)
30: Black/Green
86: Black/Orange
87A: Black
85: Black, Black (Two wires on one terminal)
87: Brown/Orange


Need to find a way to do this...

[Bitsyncmaster]

I take that back... I removed both diodes from the car and tested each individually with the meter. Neither had continuity from one side to the other.

You can pull your door diodes an use those to test after you have found and fixed the wiring problem. Door diodes are in harness beside the drivers right leg (center console). The colors of the diodes mean nothing so all are interchangeable.

[DMCMW Dave]

I take that back... I removed both diodes from the car and tested each individually with the meter. Neither had continuity from one side to the other.

Did you test the diodes in both directions? They have a polarity and will generally read open one way and a few ohms the other way.

If they are open both ways it's time for a trip to Radio Shack.

[DMCMW Dave]

You can pull your door diodes an use those to test after you have found and fixed the wiring problem. Door diodes are in harness beside the drivers right leg (center console). The colors of the diodes mean nothing so all are interchangeable.

Yeah - fix the wiring first or you'll burn them out too.

[Masaes727]

I had this same problem. I melted the whole row of relays next to the fan relays. Make sure you can cut your battery power quickly. However, after wiring in a new relay strip everything worked.

[DMCMW Dave]

I had this same problem. I melted the whole row of relays next to the fan relays. Make sure you can cut your battery power quickly. However, after wiring in a new relay strip everything worked.

That's a different problem - this is what happens if you put the lambda (2x15) relay in the fan relay socket. Dead short from unfused hot to ground. He's working on a very modified wiring setup.


Which is why there is a big sticker that says DO NOT INTERCHANGE MODULES

[ccurzio]

Check for sure, but I'm guessing you have the black (brown)/oranges (86 and 87) swapped around. I don't recall the specifics but my recollection is that the schematic colors don't match the wire colors, and that they use the orange trace for different purposes.
I pretty much ignored the factory wiring schematic and was relying solely on Toby's included instructions that came with the mod kit.



The solid brown should be going to the breaker, and the breaker should be feeding the two 87s. This is the power source for the relays that ultimately powers the fans.

There are two circuit breakers. The first one has Brown/Orange from the battery on the BAT terminal, and Black/Orange to Socket 1 on the AUX terminal. The second breaker has a Brown wire which (presumably) goes to the battery since it carries 12v. That's connected to the BAT terminal on the breaker, along with the wire to the starter solenoid. There are three other connectors, all of which have solid brown wires that go into the loom. None connect directly to the sockets. (I wish I knew which wire did what, but it's pretty terrible since they're ALL BROWN. :()



The two 30s should be feeding the two fans respectively when the relay is engaged. (Black/Green?)

Check.



The 86s should be the trigger wiring coming from the two diodes. If that traces back to the circuit breaker that's your problem, this would energize the relays all the time.

You've lost me on this one.



The 85s should be ground (relay coil ground)

Pretty sure this is correct.



The two 87a should be ground (this grounds the motors when off)

Also pretty sure this is right.



If you have fed the fans from the diode circuit, as I said before, you have probably smoked the diodes.

Just ordered four more from DMCH. (I don't suppose you can get these things locally...)



PS - do you have a real name?

Chris. :)

[Masaes727]

That's a different problem - this is what happens if you put the lambda (2x15) relay in the fan relay socket. Dead short from unfused hot to ground. He's working on a very modified wiring setup.


Which is why there is a big sticker that says DO NOT INTERCHANGE MODULES

It did make for a two day crash course in wiring 101 though. :smackbum:

[ccurzio]

Did you test the diodes in both directions? They have a polarity and will generally read open one way and a few ohms the other way.

I did indeed. No continuity in either direction on either diode.

[ccurzio]

You can pull your door diodes an use those to test after you have found and fixed the wiring problem. Door diodes are in harness beside the drivers right leg (center console). The colors of the diodes mean nothing so all are interchangeable.

According to DMCH, white diodes are 3A and black diodes are 1A.

Either way, I ordered four more of the 1A diodes.


Yeah - fix the wiring first or you'll burn them out too.

Indeed. I just wish this spaghetti was a little more coherent. :(

[Bitsyncmaster]

According to DMCH, white diodes are 3A and black diodes are 1A.

Either way, I ordered four more of the 1A diodes.



Indeed. I just wish this spaghetti was a little more coherent. :(

I know I've got red diodes and I think I have a blue one.

[DMCMW Dave]

There are two circuit breakers. The first one has Brown/Orange from the battery on the BAT terminal, and Black/Orange to Socket 1 on the AUX terminal. The second breaker has a Brown wire which (presumably) goes to the battery since it carries 12v. That's connected to the BAT terminal on the breaker, along with the wire to the starter solenoid. There are three other connectors, all of which have solid brown wires that go into the loom. None connect directly to the sockets. (I wish I knew which wire did what, but it's pretty terrible since they're ALL BROWN. :()
----
Just ordered four more from DMCH. (I don't suppose you can get these things locally...)

Chris. :)

The breaker with two wires on it is the breaker for the cooling fans. This is the one you are dealing with. With the new modification it should be hot all the time on one side, and the other side should be feeding your modified relay setup.

The other one (that should have 4 wires) is the blower (and the starter, but the starter is on the hot side of the breaker). Since yours has 5 wires on it, you have another mystery.) Generally solid brown is supposed to be 12V hot but they don't follow the code on the HVAC blower wiring. Two of the three that go into the loom should be going to the fan speed relays, the third is, at this point, a mystery. This all relates to the blower circuit, so ignore it for now.

Radio Shack. But they won't have the fancy colored cases.

[ccurzio]

The breaker with two wires on it is the breaker for the cooling fans. This is the one you are dealing with. With the new modification it should be hot all the time on one side, and the other side should be feeding your modified relay setup.
That seems to be what I've got, and what the instructions have indicated:

"Locate the cooling fan circuit breaker, usually the one next to the fuse box. The cooling fan breaker should have a brown/orange wire from the battery and a black/orange wire leading to the fan fail relay socket."


The other one (that should have 4 wires) is the blower (and the starter, but the starter is on the hot side of the breaker). Since yours has 5 wires on it, you have another mystery.)
According to the instructions, that circuit breaker "should have one brown wire from the battery, and two brown wires leading to the blower 3rd and 4th speed relays." This, plus the starter wire (which is absent from the instructions and why I had my earlier problem of not being able to start the car) makes four wires. The fifth wire was an addition based on removing the wire from position #87 on Socket 2:

"Remove the brown wire from the #87 position. This wire will need to go to the BAT terminal on the cooling fan circuit breaker."

1 + 2 + 1 +1 = 5. The only real mystery is what brown wires go where. (I think I did figure out which brown wire goes to the battery - the one constantly carrying 12v.)

[ccurzio]

Here are the relevant portions from the instructions, if it helps:


To begin with, as always when working with the electrical system, disconnect the battery. These are all live, high amperage circuits. One wrong move and you could cause a very expensive melt down. Next open the relay compartment behind the passenger seat [...] Keep in mind that most cars will by now have had some modifications performed, usually the replacement of the blue fan fail relay with the three way jumper wire. The string of relays closest to the front of the car is the one where the fan anf fan fail relays are located.

If you look at the relays you will notice the terminal numbers are next to each terminal (sometimes the #30 terminal will be marked as #51). We will use those numbers in this discussion in order to end up with the wires in the right places.

The Fan Fail Relay Socket - Normally the furthest outboard in the forward relay string

Remove both black/green cooling fan motor wires that are in the #85 and #86 positions.
Remove the fan fail light wire from the center #87A position - it should be a small gauge black/orange wire. Wrap this terminal with tape and stow aside.
Remove the black wire from the #30 spot and plug it into the #87a center slot.
Insert the black jumper wire into #85.
Plug either of the two Black/Green cooling fan motor wires (removed in step one) into the #30 spot.
The Black/Orange wire at #87 stays put.
Using a blue parallel-type wire tap, connect the red jumper wire now in the #86 position to the small gauge black/orange wire in the #85 or #86 position in the adjacent fan relay socket. Be careful not to attach it to the large brown/orange or black/orange wire in the #30 spot of the fan relay.
Use another blue parallel tap and connect the new black jumper wire we put in the #85 hole to any of the black wires in the relay string (they are all grounds).
Make sure all the terminals are firmly locked into the old fan fail relay socket.


The Fan Relay Socket - Normally next to the Fan Fail Relay Socket

Remove the brown wire from the #87 position. This wire will need to go to the "BAT" terminal on the cooling fan circuit breaker, which may require removing some tape from the wiring loom to get enough slack.
Remove the large gauge brown/orange wire from #30 and put it into the #87 spot.
Plug the remaining loose black/green cooling fan motor wire into #30. The two relay sockets should now look similar, and each will control only one of the cooling fans.


The Cooling Fan Circuit Breaker Replacement

Locate the cooling fan circuit breaker, usually the one next to the fuse box. The cooling fan breaker should have a brown/orange wire from the battery and a black/orange wire leading to the fan fail relay socket. The heater blower breaker should have one brown wire from the battery and two brown wires leading to the blower 3rd and 4th speed relays. To make this part simpler and fix another potential problem in the process, I recommend replacing both of these breakers with 40 amp post-type breakers. Just be sure that the wires from the battery are connected to the proper “BAT” terminal of the new breaker. The brown wire mentioned in the paragraph above should also have a new ring terminal added and be attached to the "BAT" terminal of the new cooling fan breaker. Make sure that the breaker wires do not touch each other or short out.

Fit the new breakers into the original breaker brackets and reinstall the relay socket strips and relays. An additional Bosch-type 5 pin relay must be installed in the old fan fail relay socket.

[DMCMW Dave]

"Remove the brown wire from the #87 position. This wire will need to go to the BAT terminal on the cooling fan circuit breaker."


You have apparently connected that brown wire to the blower fan breaker. That is not what the instructions said.

[ccurzio]

You have apparently connected that brown wire to the blower fan breaker. That is not what the instructions said.

Ah, you are correct. That's true enough, but in this context it isn't related to my problem since that's just a 12v lead. Good catch, though.

[ccurzio]

Okay, so I'm back to square one. I had my meter on the wrong mode for checking the diodes yesterday. I bought a pair of new ones from Radio Shack this morning and tested them when I got home the same way I tested the old ones, and got nothing. Then I saw the ->|- symbol on the meter and tested the new ones again and they worked.

So I tested the old ones again. They worked too. That means two things:

1) The diodes are fine.
2) I wasted about $30 on replacements.

http://i.imgur.com/o7Rbz.jpg

In the meantime I can move the starter wire to the proper breaker, but I still have no functional cooling fans and I'm back to not understanding why.

[DMCMW Dave]

Try drawing the circuit out (as modified) on paper, using the colors you see and tracing the wiring to where it goes with your ohm meter.

Then see if voltages are where you expect them to be, i.e. 12V in and out of the breaker, 12V on the power lead of the relays, 12V on the relay coils only with the otterstat jumped and key on, etc. Since you do hear the relays click the grounds are probably in the right place, but check everything.

The original circuit is pretty strange as the breaker is AFTER the relay, but the mod you are doing moves the breaker BEFORE the two relays and powers it from the brown hot wire. Go back to Post 20 and see if this matches your diagram.

I still think you have a couple of wires reversed. OR an out-of-box failure of the breaker.

[ccurzio]

You know, in thinking about it I'm wondering if the relays are clicking when power is applied because I've got the otterstat jumped. That would seem to make sense...


an out-of-box failure of the breaker.
I've tested continuity across both posts on both breakers and they seem to be fine.


Try drawing the circuit out (as modified) on paper, using the colors you see and tracing the wiring to where it goes with your ohm meter.

Then see if voltages are where you expect them to be, i.e. 12V in and out of the breaker, 12V on the power lead of the relays, 12V on the relay coils only with the otterstat jumped and key on, etc. Since you do hear the relays click the grounds are probably in the right place, but check everything.
I'm still pretty new to electronics troubleshooting so a lot of this is a bit out of my reach. I'm at a total loss on this one. :(

[ccurzio]

Okay, I seem to be making some progress. I have gotten ONE of the fans working. This has been a huge pain in the ass thanks to the thing I mentioned earlier in the thread: too many wires are brown. :(

Anyway, I tore down the connections on both circuit breakers and I'm now testing each with my meter and putting them back one by one. One of the connections I thought was one thing turned out to be something else, preventing power from running to one of the circuit breakers at all. Once that was figured out and fixed, one of the fans started working.

The second one is quite a mystery though. I've tried running 12v directly to each of the wires that plugs into the other side of the circuit breaker and none of them fire up the other fan. Running power directly to the fan wire itself does work, though.

I'm getting somewhere I guess. :(

[ccurzio]

All fixed!

Seems it was a matter of quintuple-checking all circuit breaker connections. If they were all marked properly I would have had this mess done yesterday, but it's not easy dealing with a mass of identical brown wires.

Thanks for your help, everyone!

[Dangermouse]

Good job!!!

While its fresh in your mind, put some sort of mark or number on those wires and on the drawing now that you have worked out which is which.

[ccurzio]

Good job!!!

While its fresh in your mind, put some sort of mark or number on those wires and on the drawing now that you have worked out which is which.

Definitely. I'm also going to label which relay controls which fan. (Which is rather logical anyway since the way I have it wired, the passenger-side relay controls the passenger-side fan and the driver-side relay controls the driver-side fan.)

Someone has definitely been mucking around with this wiring before I ever owned the car. Much of it didn't match original spec - especially considering the starter solenoid power wire started off on the wrong circuit breaker.

Thanks. :)