IRCM problem

the-big-e

the-big-e

Registered User
Black Betty is having a problem remaining cool while driving......:rolleyes:

Her low speed fan quit working and she will heat up until the high speed fan comes on and cools her down a bit.....

Both the high and low speeds of the fan operate when directly connected to the battery......:rolleyes:

I hooked my IC fan up to one of the hot wires on the fan (so I could run her at the 06 shoot-out) and it comes on when the high speed fan comes on.....

I have since cut that wire, but there is still no low speed fan......

Am I having a problem with the ECC or am I overlooking something......:confused:

I have gone through 6 IRCMs and still no low speed fan.......:mad:

What are the odds that all 6 IRCMs are bad........:eek:
 
You may have blew diode hooking up additional fan at show

Do this, leave key off. disconnect the 12 pin connector thats on the top left of your supercharger. No need to disconnect the single pin connector. Then disconnect connector that goes to ac compressor, a 2-wire connector and measure resistance on the connector to read that diode. You may have to swap leads once or twice to get a reading.You will get 0 resistance one way , BUT WILL READ RESISTANCE THE OTHER WAY. TRY TO GET A READING. if you can't get a measurement both ways then you blew your diode. My diode reads 2.176 Mega ohms with my fluke 87 one way, and zero ohms the other way. My diode is good. If your reading aint close to this you
gotta bad diode.


PS if your meter has a diode selection you get .554 volts one way, and zero
volts the other way. This means its good. Bad diode you get 0 volts both ways.
 
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There has been so much discussion about this that I'm worried that misinformation may now be running around. With the key on, +12V to the Tan/Orange wire will engage the low speed fan relay. The popular suggestion is to cut the wire to get the fan to always run.

What happens, when that wire is cut, is the relay circuitry "floats" and pulls up to battery voltage. That fake signal is inverted so that the relay engages.

The best way to insert a manual override is not to cut the wire but rather splice in a parallel 12V switched source. BTW, this can be done entirely from inside the car at the EEC connector in the passenger side under the dash.

Since you have a couple of spare birds, you might try swapping IRCMs and fans around a bit. You can usually push a partially unfolded paper clip about 1/2" into the IRCM connector housing at the #14 pin, and then apply 12V momentarily to it. You don't have to wait till the engine heats up to see if it works.

You may also have a wire break somewhere in that tan/orange wire between the EEC and the IRCM.
 
I'll do the diode check and the paper clip check when I get back to work.....

Where do you think all the IRCMs came from......:p
 
Watching this thread. I too have fan troubles. (posted on an Ontario thread)

If I do this
"You can usually push a partially unfolded paper clip about 1/2" into the IRCM connector housing at the #14 pin, and then apply 12V momentarily to it."
What does it tell me?
Fan works=?
Fan doesn't work=?
 
If one of the fans is inoperative, you can test the fans individually. First check to make sure that there is power on the BK/O wire going to the IRCM, that is the main power for it. If power is good there, you can jump the terminals using a fused jumper wire ( a wire with a fuse in the middle some where so that you don't burn something up ). Jump the BK/O wire to the BR/Y wire, that should start the low speed fan. Next jump the BK/O wire with the BR/O wire, that should start the high speed fan. If both fans operate, either the IRCM is bad or the wire to the fan in question is open, which can be checked with a continuity test. If the fan still does not work, the fan needs to be replaced.
 
the-big-e said:
I hope not....:(
Click to expand...
Actually, I owe a correction. It would not be a wire break, but a short. A break would make the fan run, a short would keep it from running. But also, shorts usually cause fuses to blow out. Electrical problems are fun, aren't they? :rolleyes:
 
TbirdSCFan said:
Actually, I owe a correction. It would not be a wire break, but a short. A break would make the fan run, a short would keep it from running. But also, shorts usually cause fuses to blow out. Electrical problems are fun, aren't they? :rolleyes:
Click to expand...

But I can still check for continuity between the EEC and the IRCM.....
 
Eddie, you know if you need any technical info you can just call me. If you need me to look up something, call me in the evenings or on the weekends. Now as for parts, I think you have me beat now.
 
vlouis90sc said:
Do this, leave key off. disconnect the 12 pin connector thats on the top left of your supercharger. No need to disconnect the single pin connector. Then disconnect connector that goes to ac compressor, a 2-wire connector and measure resistance on the connector to read that diode. You may have to swap leads once or twice to get a reading.You will get 0 resistance one way , BUT WILL READ RESISTANCE THE OTHER WAY. TRY TO GET A READING. if you can't get a measurement both ways then you blew your diode. My diode reads 2.176 Mega ohms with my fluke 87 one way, and zero ohms the other way. My diode is good. If your reading aint close to this you
gotta bad diode.


PS if your meter has a diode selection you get .554 volts one way, and zero
volts the other way. This means its good. Bad diode you get 0 volts both ways.
Click to expand...

For some reason, I can't get any reading using resistance.....:mad:

I have checked three different systems and got the same results.....

I'll be the first to admit that I am not the best electrican, yet.....:rolleyes:
 
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