DINO84

My power seat circuit breaker gets real hot and this resistor? starts smoking!The circuit breaker only powers for a second before it trips.This connector is inside the console.Does anyone know what it is?does?And how to fix it?My seat is stuck in the short and up position.Not very comfortable to me.BTW:Its a 91 coupe.

jfb

That isn't a resistor, it is a diode which conducts voltage pulses when the motor is turned off to protect the ECM and other solid state electronic devices. The diode does not conduct with the polarity applied to the motor. In your case, it is likely that the diode has failed shorted and this is why it smokes and your circuit breaker trips. They aren't expensive and you can test the diode with an ohmeter. If it is shorted an ohmeter will show very low resistance (under a couple ohms) with your ohmeter probes connected either way across the diode leads.

DINO84

Thank you.I'm chasing a short and hoped this was it.Would radio shack have a replacement?

Chuck Tribolet

Maybe, if you knew the specs. If not, Mouser Electronics would VERY
likely have it, if you knew the specs.

If you don't have the specs, you are like going to need the GM
replacement part. Note that it must be installed the correct way
round.


Chuck

DINO84

Good info.Thanks

DINO84

OK,I got 0 ohms reading.I called my local chevy dealer and he said the connector is no longer available.I checked online and there connectors don't have the diode attached.I went out with a magnifying glass and got these numbers from it.9047 505-300 GI .While checking with some diode dist. they say the numbers no good.Should I just try and get one from a used corvette? Does anyone know if I can get the correct diode?Thanks

Rich B.

If you have the 8-digit GM part number (your dealer must have had it if he knows it's not available) just plug it into Google...I've come up with a bunch of dealers, aftermarket parts suppliers, junk yards, even private owners who had the part I needed...*Especially* electrical parts...

Also, most GM parts are shared across models and brands...So if you do Google it, specifying Corvette may not turn up a Cadillac part that is the same thing...

DINO84

Googling didn't help.I did find a forum thread that said they got one at radioshack but it didn't list a part number.So close!I'm still not understanding what its purpose is?Does it send power spikes to the neg side to trip the circuit breaker?

Keystring

No.

It prevents spikes from returning back into the circuit to prevent an overload which would otherwise trip the breaker or fry the circuit.

This diode has the 'negative' side tied to ground to prevent spikes and limit the current draw on the circuit.

If either your motor winding or some other part of the circuit develops a short or heavy draw, the diode is designed to 'short to ground' to stop the flow of current to the circuit to prevent any more damage.


Removing it may return the circuit back to operation BUT you will have no over current protection.

I would remove the diode and then test the circuit for current draw to try to determine why the diode shorted in the first place.

DINO84

OK,Thanks.So how do I determine what size diode to replace it with?Its a 30 amp circuit breaker.Is that a clue?

Keystring

You should be able to use a 1N5401 diode.

It has a 3 amp 100 volt rating which should be sufficient.

DINO84

OK,THanks,

DINO84

I ended up with a 50v 3 amp diode.The next size up was 200v 3 amp.I hooked it up and everything works again.Thanks everyone!