Cooling fan capacitors

[Bitsyncmaster]

I have a customer having problems with my Fan fail. It sounds like an electrical noise issue. So I was going to disconnect the two stock 2.2 uf capacitors on my D that are stock and see if I can see the same problem. But I can't find those capacitors. Anyone know where they are located?

[DMCVegas]

99% certain they're in the wiring harness themselves. You should be able to just follow the wires back from the Fans on the Frame Harness, and you'll find them.

You can see them on the left side of this picture:

http://store.delorean.com/images/Product/large/108599.JPG

[dn010]

It depends on the harness.

Early harnesses never had those capacitors.

Later ones did and they were located right before the plug (harness side) going to the fan motor.

Unfortunately, I cannot tell you when the change happened but you are able to tell whether you have them or not by how many wires are coming out of the harness side fan connector. If you've got 2 black wires on one side and a yellow wire & green wire crimped on the other, you have them. If you have 1 black and 1 green per connector, you don't.


I have a customer having problems with my Fan fail. It sounds like an electrical noise issue. So I was going to disconnect the two stock 2.2 uf capacitors on my D that are stock and see if I can see the same problem. But I can't find those capacitors. Anyone know where they are located?

[DMCMW Dave]

It depends on the harness.
.

They are usually pretty simple to remove. They are an extension of the harness, i.e. unplug both ends and connect the fan to the harness. Not consistent across all production though.

[Bitsyncmaster]

It depends on the harness.

Early harnesses never had those capacitors.

Later ones did and they were located right before the plug (harness side) going to the fan motor.

Unfortunately, I cannot tell you when the change happened but you are able to tell whether you have them or not by how many wires are coming out of the harness side fan connector. If you've got 2 black wires on one side and a yellow wire & green wire crimped on the other, you have them. If you have 1 black and 1 green per connector, you don't.

Mine were about a foot back from the fan connectors. I could not see them because I have the rubber fan shroud hiding the harness at the center location. I removed them and unwrapped the harness to do that. One read 2.2 uf the other 2.0 uf. I don't think I will put them back in but it's a good excuse to install new socket pins in the harness side.

I tested that fan fail unit the customer returned without the capacitors and saw no problems running without the capacitors.

[novadmc]

the caps were only to absorb excess power draw from the stock fans (basically a noise filter), correct?

so pretty much not needed at all if the customer is running upgraded low power draw fans, yes?

[gullwinger]

Mine were about a foot back from the fan connectors. I could not see them because I have the rubber fan shroud hiding the harness at the center location. I removed them and unwrapped the harness to do that. One read 2.2 uf the other 2.0 uf. I don't think I will put them back in but it's a good excuse to install new socket pins in the harness side.

I tested that fan fail unit the customer returned without the capacitors and saw no problems running without the capacitors.

Hey Dave,
I have the capacitors near my fans like your car. Could be noise in my car like you said. My DPI fans look great I just want to get rid of that damn stock fan fail relay. Hope we can get to the bottom of this. thanks
Jason S

[dn010]

How did you connect your fans to your harness?

If you received the same setup I did from DPI, it came with butt splice connectors. I threw those in the garbage and crimped on a 2-pin weatherpack. That connection sees a lot of moisture / rain and corrodes so I did not want to splice the original connector on and did not want to use the supplied butt splice connectors.

Maybe you just have a bad or loose connection from harness/fan?


Hey Dave,
I have the capacitors near my fans like your car. Could be noise in my car like you said. My DPI fans look great I just want to get rid of that damn stock fan fail relay. Hope we can get to the bottom of this. thanks
Jason S

[Bitsyncmaster]

the caps were only to absorb excess power draw from the stock fans (basically a noise filter), correct?

so pretty much not needed at all if the customer is running upgraded low power draw fans, yes?

It's normal to use a capacitor and or diode on electric motors to reduce electrical noise. I try to design without needing those filters so I'm going to leave them out. I did put a diode on my AC compressor clutch to kill a noise problem with my battery relay.

[gullwinger]

I used solder and a heat shrink wrap on the wires. No problems with jumpers.

[David T]

I used solder and a heat shrink wrap on the wires. No problems with jumpers.

The caps are for filtering out noise created by the OEM style motors with brushes. Newer type fan motors don't use brushes but can create their own different kind of electrical noise not easily removed with simple caps. Newer radios are better at filtering out noise from the electrical system. If you try to receive weak radio signals (not satellite) expect to pick up all kinds of noises. Especially if you are in rural and/or mountainous areas. Because of the age of the caps their effectiveness at this point is questionable. They were not meant to last forever and do age.

[Bitsyncmaster]

The caps are for filtering out noise created by the OEM style motors with brushes. Newer type fan motors don't use brushes but can create their own different kind of electrical noise not easily removed with simple caps. Newer radios are better at filtering out noise from the electrical system. If you try to receive weak radio signals (not satellite) expect to pick up all kinds of noises. Especially if you are in rural and/or mountainous areas. Because of the age of the caps their effectiveness at this point is questionable. They were not meant to last forever and do age.

I don't think you will find a radiator fan motor that does not use brushes. Not saying you can't make your own setup with a brushless motor.

[David T]

I don't think you will find a radiator fan motor that does not use brushes. Not saying you can't make your own setup with a brushless motor.

I think the new Spaal fans are brushless DC motors.

[Bitsyncmaster]

I think the new Spaal fans are brushless DC motors.

Can you link a data sheet?

From what I've seen, there are some expensive brushless motors that may be 5 to 10% more efficient. But who is going to drop $600 for a pair of those motors. Yes they will last longer.

[Elvis]

little aerodynamic improvement and brushless is the only way I see how the
newer fans can be better. maybe 10...15%

Like I always say -I don't believe in a so much better efficiency.
Probably it's the lower airflow and therefore much less powerdraw...one
fine day I'll measure it.