No Interoir Fan... No Heat No AC...

[DKDMC]

My Air and Heat does not work. So I did the relay kit update, cleaned and checked the fan switch, and rebuilt the mode switch. Nothing. What is next? I would love to get some air in my car. lol. This is a frustrating project!

Thanks for the help.

[Mattglas]

Have you made sure that the blower works? It's under the dash on the passenger side.

[DKDMC]

Have you made sure that the blower works? It's under the dash on the passenger side.

what is the best way to test that?

[Mattglas]

Pull off the pink/black wire and the black wire connecting to it and probe it with a multimeter. If they're geting power it's probably the motor.

[OverlandMan]

what is the best way to test that?

The positive and negative terminals are on the unit itself in the lower right corner under the passenger foot well/dash. I would throw fused/breakered power at it and see if it comes on. If it does, see if its getting 12v(+) from the switch. I use a power probe but you could just make a fused test wire in a pinch.

[Bitsyncmaster]

Pull off the pink/black wire and the black wire connecting to it and probe it with a multimeter. If they're geting power it's probably the motor.

You really need to "probe" power with the load attached. A marginal connection would show full voltage when the load is removed but almost zero volts with the load left connected.

[AugustneverEnds]

It seems like you will be poking your head into the passenger footwell so you should also have a look at the blower motor resistor (this: http://store.delorean.com/p-7593-resistor.aspx) When I got my car four years ago the blower did not work at all because the resistor was missing.

[DKDMC]

Sounds like I have a lot to check out this evening! I'm determined to get some AIR!!

[David T]

Sounds like I have a lot to check out this evening! I'm determined to get some AIR!!

If the cabin fan isn't working the first thing to check is if it is getting power. Another way would be to just put power and ground directly to the fan motor and see if it works. Chances are the motor is no good and enough refrigerant has leaked out that you won't get any air. I would just pull the fan motor out and see if even turns. If it does turn easily put some power on it with some jumper cables. Once you get a fan motor working you will probably have to replace the hoses, seals, and dryer and refill with refrigerant to get A/C.

[DKDMC]

If the cabin fan isn't working the first thing to check is if it is getting power. Another way would be to just put power and ground directly to the fan motor and see if it works. Chances are the motor is no good and enough refrigerant has leaked out that you won't get any air. I would just pull the fan motor out and see if even turns. If it does turn easily put some power on it with some jumper cables. Once you get a fan motor working you will probably have to replace the hoses, seals, and dryer and refill with refrigerant to get A/C.

Awesome. Thank you! I'll let you all know what my findings are!

[DKDMC]

If the cabin fan isn't working the first thing to check is if it is getting power. Another way would be to just put power and ground directly to the fan motor and see if it works. Chances are the motor is no good and enough refrigerant has leaked out that you won't get any air. I would just pull the fan motor out and see if even turns. If it does turn easily put some power on it with some jumper cables. Once you get a fan motor working you will probably have to replace the hoses, seals, and dryer and refill with refrigerant to get A/C.

Ok! So I got power to the blower and it fired right up! So what is wrong? I checked the relay compartment and fuses once again did not find anything out of place. Could it be a bad fan speed switch? Still a mystery.

[sdg3205]

Check the connectors on the back of the knobs. Its not impossible to have the connectors/Harnesses behind the HVAC panel come loose.

[DKDMC]

Check the connectors on the back of the knobs. Its not impossible to have the connectors/Harnesses behind the HVAC panel come loose.

Good idea thank you. It's all connected. Just re checked. mode switch just rebuilt and I have the center console out until I finish this mystery along with some other work. I just want this fan to turn on properly!

[DMC5180]

Do have a 12v test light probe?


Dennis

[DKDMC]

Do have a 12v test light probe?


Dennis

I don't but I will get one!

I pulled the resistor out. Looks old but doesn't look broken in any way. Should I just replace it? Here are photos

4609646096

46096
I have taken the center console out and gone through all the wiring. The vacuum system seems to be working perfectly. The vents open and close properly when I adjust the mode switch. But still no blower working. Could a bad fan speed switch keep the blower from operating completely? Perhaps this is a relay issue after all...

Also there are three wires going to the blower. Pink/black and two black wires. Is there a diagram for this? I want to make sure it is hooked up properly before moving on to the relays.

[DMC5180]

Your resistor looks to be in great shape. No need to replace it.

Did have the wires off the mode switch? Better yet post a photo of the mode switch connections.

Pink/black wire is regulated + Voltage. Fan speed 1-3 thru the resistor, 4 is direct power. All black wires are ground sides of any circuit in the delorean.

Verify the Fan speed breaker connections are good.


Dennis

[DKDMC]

Your resistor looks to be in great shape. No need to replace it.

Did have the wires off the mode switch? Better yet post a photo of the mode switch connections.

Pink/black wire is regulated + Voltage. Fan speed 1-3 thru the resistor, 4 is direct power. All black wires are ground sides of any circuit in the delorean.

Verify the Fan speed breaker connections are good.


Dennis

Thanks Dennis.

Here is a pic of mode and speed switches.

46101

46102

[DMC5180]

The mode switch wires appear to be in the correct position. Hard to tell in that photo. Have you checked the #10 fuse.

Do you know if you have any system charge in your A/C? You need at least 30Psi in the system to close the LP switch. That will cause the A/C compressor clutch to POP,CLICK and force the Radiator fans to run. This would at least verify if you have power through the mode switch. Key ON Engine NOT running.

Here is the schematic you were looking for. NOTE: The blower fan circuit is independent of the A/C, but happens to be be included in this illustration. You really just need a 12V test probe and start checking the circuit wires as shown, key ON.

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

Another thing you can do, if you have a DVM, is to confirm Ground continuity from the fan motor body to any chassis component. (steering column, Manual shift lever etc. I've seen the Ground cluster lose continuity at screw connection of the motor housing. I normally just use the Audible continuity feature on the DVM for this. it should read near zero resistance.

http://dmctalk.org/showthread.php?13342-DeLorean-Ground-Schematic

[DKDMC]

The mode switch wires appear to be in the correct position. Hard to tell in that photo. Have you checked the #10 fuse.

Do you know if you have any system charge in your A/C? You need at least 30Psi in the system to close the LP switch. That will cause the A/C compressor clutch to POP,CLICK and force the Radiator fans to run. This would at least verify if you have power through the mode switch. Key ON Engine NOT running.

Here is the schematic you were looking for. NOTE: The blower fan circuit is independent of the A/C, but happens to be be included in this illustration. You really just need a 12V test probe and start checking the circuit wires as shown, key ON.

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

Another thing you can do, if you have a DVM, is to confirm Ground continuity from the fan motor body to any chassis component. (steering column, Manual shift lever etc. I've seen the Ground cluster lose continuity at screw connection of the motor housing. I normally just use the Audible continuity feature on the DVM for this. it should read near zero resistance.

http://dmctalk.org/showthread.php?13342-DeLorean-Ground-Schematic

Thank you. Extremely helpful. Just to clarify, my blower fan should work regardless of the Ac compressor working or not correct? I'm sure it needs charging or a complete overhaul but I at least want the blower functional to start with.

[DMC5180]

Thank you. Extremely helpful. Just to clarify, my blower fan should work regardless of the Ac compressor working or not correct? I'm sure it needs charging or a complete overhaul but I at least want the blower functional to start with.

Correct

[DKDMC]

Correct

So I have poked around with my multimeter. It seems I have no power at my fan circuit breaker... What could be the cause of that?

Frustrated :/

[Bitsyncmaster]

So I have poked around with my multimeter. It seems I have no power at my fan circuit breaker... What could be the cause of that?

Frustrated :/

I'm assuming you check both sides of the breaker. So you have a broken connection since the blower power would come directly from the battery. You would need to pull the wood panel off the back to get to the junction of wires coming from the battery.

[DKDMC]

I'm assuming you check both sides of the breaker. So you have a broken connection since the blower power would come directly from the battery. You would need to pull the wood panel off the back to get to the junction of wires coming from the battery.

I did check both sides. I'll pull the panel tonight and see what I can find.

[David T]

I did check both sides. I'll pull the panel tonight and see what I can find.

The power for the radiator fans circuit breaker comes out of Relay 112 (T). You need to check for power there if you don't have any power at the circuit breaker. It is in the bottom row 2nd from the left. One big thing to look for is if any terminals have worked their way loose and "backed out" of their position in the plastic block so that the terminals of the relays do not make contact when inserted.

[DMC5180]

Very strange, the blower fan feed wire comes from a large crimp clustered brown wire junction. Just for grins, do a continuity test between the breaker terminals and POS battery terminal.

All Solid brown wires are +12v LIVE feeds.





Dennis

[David T]

Very strange, the blower fan feed wire comes from a large crimp clustered brown wire junction. Just for grins, do a continuity test between the breaker terminals and POS battery terminal.

All Solid brown wires are +12v LIVE feeds.

Dennis

Before you do that continuity check disconnect the battery! My wiring poster shows the power coming from that cluster and going to the fan relay and then on to the circuit breaker. There are differences among the cars, maybe some got wired differently. If everything else coming out of that cluster has power I would doubt that is where the problem is. Are you sure you are correctly checking for power? Do you have a good ground? Can you measure power anywhere else?

[DKDMC]

Before you do that continuity check disconnect the battery! My wiring poster shows the power coming from that cluster and going to the fan relay and then on to the circuit breaker. There are differences among the cars, maybe some got wired differently. If everything else coming out of that cluster has power I would doubt that is where the problem is. Are you sure you are correctly checking for power? Do you have a good ground? Can you measure power anywhere else?

Yes I've been Able to measure properly in multiple locations. Could a bad fan speed switch cause this?

[DMC5180]

Yes I've been Able to measure properly in multiple locations. Could a bad fan speed switch cause this?

No .The fan speed switch is down stream of the fan breaker. You stated you didn't have power at the fan breaker.


Dennis

[David T]

Before you do that continuity check disconnect the battery! My wiring poster shows the power coming from that cluster and going to the fan relay and then on to the circuit breaker. There are differences among the cars, maybe some got wired differently. If everything else coming out of that cluster has power I would doubt that is where the problem is. Are you sure you are correctly checking for power? Do you have a good ground? Can you measure power anywhere else?

Please disregard the above, previous, post.
I confused the cabin fan and the radiator fans. The circuit breaker for the cabin fan is directly powered from the N (brown) cluster. Since that is before the fan switch, a bad fan switch can't cause a loss of power at the circuit breaker. If you don't have power on the brown wire there is a break between the circuit breaker and the N cluster.

[DKDMC]

No .The fan speed switch is down stream of the fan breaker. You stated you didn't have power at the fan breaker.


Dennis

Thanks Dennis. Makes sense. This has been a tough one. I'll keep digging through and testing..

[DKDMC]

Please disregard the above, previous, post.
I confused the cabin fan and the radiator fans. The circuit breaker for the cabin fan is directly powered from the N (brown) cluster. Since that is before the fan switch, a bad fan switch can't cause a loss of power at the circuit breaker. If you don't have power on the brown wire there is a break between the circuit breaker and the N cluster.

Thanks David!

[DMC5180]

Before you do that continuity check disconnect the battery!

YES, for SAFETY reasons. If a person were to accidentally touch a grounded surface with the probe opposite the battery, it would NOT be good.

[DKDMC]

Verified all connections. Everything seemed to be connected properly. Finally pulled off the fan speed switch and jumpered it. BAM!!! Blower comes on. I have a new fan speed switch on the way. What a frustrating couple weeks. Thank you all for your help. This community is amazing. On to the next adventure. Cold air conditioning!

[DMC5180]

Congratulations. That's a rare failure.

I'm curious though, If jumping around the switch yielded success, then you did have power at the fan breaker. Did you error in your testing for power there? Or did you find an issue there too.


Dennis

[David T]

Congratulations. That's a rare failure.

I'm curious though, If jumping around the switch yielded success, then you did have power at the fan breaker. Did you error in your testing for power there? Or did you find an issue there too.


Dennis

Or perhaps you were checking the wrong breaker? The one next to it is the one for the rad fans. As for the fan switch, before you say it is bad you must be sure the connections are on it correctly. Assuming it is good, when you get the new one and hook it up the way the old one was connected (and if it was connected wrong) the new one won't work either.

[DKDMC]

Or perhaps you were checking the wrong breaker? The one next to it is the one for the rad fans. As for the fan switch, before you say it is bad you must be sure the connections are on it correctly. Assuming it is good, when you get the new one and hook it up the way the old one was connected (and if it was connected wrong) the new one won't work either.

I did make a mistake with the breaker test. It was the breaker for the rad fans and of course no power because the car was not on or at the proper temp for them to trip on.

I will definitely check that all wires are properly in the yoke for the fan speed switch. They seem to be. But I am putting in a brand new switch either way. I don't want to remove the center console and entire hvac panel to deal with this again. Putting in a new stereo and speakers and upgrading all the illumination bulbs as well. Might as well do it all while everything is torn apart.

[DMC5180]

As long as you have the fan switch out, do some continuity testing on the terminals with the shaft in multiple positions. This will confirm if it's truly dead.


Dennis

[Bitsyncmaster]

As long as you have the fan switch out, do some continuity testing on the terminals with the shaft in multiple positions. This will confirm if it's truly dead.


Dennis

Could also pull the old switch apart. Probably will see burned copper traces.

[DKDMC]

As long as you have the fan switch out, do some continuity testing on the terminals with the shaft in multiple positions. This will confirm if it's truly dead.


Dennis

New switch arrived today. Installed and working perfectly. I noticed the click when switching modes is much more pronounced then the old switch. For 20 bucks it was worth getting a brand new switch.

[DMC5180]

New switch arrived today. Installed and working perfectly. I noticed the click when switching modes is much more pronounced then the old switch. For 20 bucks it was worth getting a brand new switch.

[emoji106]


Dennis

[David T]

As long as you are in there you should be lubricating the vacuum part of the mode switch if not replacing the rubber. Other things to check while you have the console apart;

Put some stiffeners in the lower front edges of the console
Make sure you get the boot to the center vents back on correctly
Connect the dimmer switch and lighter outlet correctly
Don't pinch any wires or hoses when you reinstall the console
Since you are replacing the stereo and speakers you should also replace the speaker wiring.

Good find on the bad fan switch.

[Rich]

....I don't want to remove the center console and entire hvac panel to deal with this again. Putting in a new stereo and speakers and upgrading all the illumination bulbs as well. Might as well do it all while everything is torn apart.

David has a good list going. One more to add.

While there be sure to look for this part around your shifter.
The noise isolator: LINK:http://store.delorean.com/p-8649-noise-isolator-mt.aspx (http://store.delorean.com/p-8649-noise-isolator-mt.aspx)

Our early-VIN D didn't come with one and yours probably didn't either although a PO may have added it. What DMCH says about it is true.


DMCH: "Many DeLoreans left the factory without this part, as it came along several months after production started as a running change. It's a bit of a chore to install, but if you have your console out (putting in a stereo, perhaps?) take a look at hole in the underbody where the shift mechanism protrudes. If it doesn't have this rubber part shown here fitted, you're getting extra heat and noise into the passenger cabin. Also available for automatic transmission cars under part number 110184."

[DKDMC]

As long as you are in there you should be lubricating the vacuum part of the mode switch if not replacing the rubber. Other things to check while you have the console apart;

Put some stiffeners in the lower front edges of the console
Make sure you get the boot to the center vents back on correctly
Connect the dimmer switch and lighter outlet correctly
Don't pinch any wires or hoses when you reinstall the console
Since you are replacing the stereo and speakers you should also replace the speaker wiring.

Good find on the bad fan switch.

Thanks Dave. I did the rebuild kit from DMC, Lubricated with silicone, its good to go for another 30 years hopefully!

Took the whole center console apart.
Definitely will make sure the vent boots are on
Replacing all the bulbs
Zip tying some of the sloppy wiring to clean it up back there
Monster Cable is going in for sure... The speakers and wiring are all original.. Can't wait to have real sound!
:driving1:

[DKDMC]

David has a good list going. One more to add.

While there be sure to look for this part around your shifter.
The noise isolator: LINK:http://store.delorean.com/p-8649-noise-isolator-mt.aspx (http://store.delorean.com/p-8649-noise-isolator-mt.aspx)

Our early-VIN D didn't come with one and yours probably didn't either although a PO may have added it. What DMCH says about it is true.


DMCH: "Many DeLoreans left the factory without this part, as it came along several months after production started as a running change. It's a bit of a chore to install, but if you have your console out (putting in a stereo, perhaps?) take a look at hole in the underbody where the shift mechanism protrudes. If it doesn't have this rubber part shown here fitted, you're getting extra heat and noise into the passenger cabin. Also available for automatic transmission cars under part number 110184."

I noticed that as soon as I removed the shift plate! It is ordered and on its way! That should help quite a bit! They must have been in a rush when they put our early cars together.

[David T]

Thanks Dave. I did the rebuild kit from DMC, Lubricated with silicone, its good to go for another 30 years hopefully!

Took the whole center console apart.
Definitely will make sure the vent boots are on
Replacing all the bulbs
Zip tying some of the sloppy wiring to clean it up back there
Monster Cable is going in for sure... The speakers and wiring are all original.. Can't wait to have real sound!
:driving1:

Monster cable is kind of overkill but can't hurt. The main reason for replacing the wiring is to get rid of the common ground. Most newer radios can't work properly with that common ground. If you are getting a radio with a lot more power you may also want to replace the power and ground with larger gauge and more direct connections.

[DKDMC]

Monster cable is kind of overkill but can't hurt. The main reason for replacing the wiring is to get rid of the common ground. Most newer radios can't work properly with that common ground. If you are getting a radio with a lot more power you may also want to replace the power and ground with larger gauge and more direct connections.

I am a bit of an audiophile.. The car already had a pioneer CD setup that may be 5-6 years old. Im upgrading to a Pioneer MVH-X380BT unit with no CD player. I have the monster cable.. so might as well put it in! New JBL GTO429 Fronts and KENWOOD KFC-415C Rears.

[John U]

New switch arrived today. Installed and working perfectly. I noticed the click when switching modes is much more pronounced then the old switch. For 20 bucks it was worth getting a brand new switch.

Where did you get a new mode switch?
Didn't see it on the dmch site.
Mine was a mess.

[Rich]

Where did you get a new mode switch?
Didn't see it on the dmch site.
Mine was a mess.

You are asking about a new mode switch. Not seen at DMCH, correct.

The OP is talking in post 39 about a new fan speed switch, different part, no? Maybe the OP can comment.

Post 41 mentions lubing the mode switch on the side.

[DKDMC]

Where did you get a new mode switch?
Didn't see it on the dmch site.
Mine was a mess.

You need to buy the mode switch rebuild kit from DMCH. It replaces the worn out diaphragm. Easy fix. Makes it brand new

[John U]

My diaphragm was already replaced. The metal switch part was very corroded. I cleaned it up and it works well now. Was just wondering if they were available now. They weren't before.
I am Talking about the mode switch not fan speed switch.

[DKDMC]

My diaphragm was already replaced. The metal switch part was very corroded. I cleaned it up and it works well now. Was just wondering if they were available now. They weren't before.
I am Talking about the mode switch not fan speed switch.

Ah. I see. No I have not seen any new available. Perhaps you could find a used one in better shape then yours on ebay or another source.

[John U]

I managed to clean it up and it works well. I was just hoping there was a source in case it crapped out again.