ECM problem
Thread Starter
Intermediate
Joined: Oct 2003
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From: LAUDERDALE MS
ECM problem
Hey,
I've got a series of problems on my poor C4. Engine Fan doesn't turn even if engine temperature is getting high and the A/C fan doesn't turn when A/C is turned on. I tested the motors and relays plus A/C coolant switch and engine temperature gauge... everything seems to work. It should be weither a wire problem or the entire ECM. Does someone have the electrical system scheme for a 91 vert?
Thanks for advice
Arnaud
I've got a series of problems on my poor C4. Engine Fan doesn't turn even if engine temperature is getting high and the A/C fan doesn't turn when A/C is turned on. I tested the motors and relays plus A/C coolant switch and engine temperature gauge... everything seems to work. It should be weither a wire problem or the entire ECM. Does someone have the electrical system scheme for a 91 vert?
Thanks for advice
Arnaud
Le Mans Master
Joined: Feb 2000
Posts: 9,715
Likes: 27
From: Kempner Texas
Re: ECM problem (Kermach)
Just last night I was at a buddy's shop and he's having fan trouble too. 1986.
His fan wouldn't come on even when the coolant temp reached 242 F.
Put 12 V to the relay and still nothing; then put 12 volts directly from the battery to the wire leading to the fan, downstream of the relay and the fan came on, would run for a period of time, then suddenly cut off, only to restart again after a few minutes. All the while the engine was idling.
We checked to make sure the 12 V was still connected and it was.
He had just bought and installed a new relay too thinking the relay was the cause.
So in his case it seems like the fan motor, itself, is the problem.
When I jumpered the A&B terminals on the ALDL the fan WOULD NOT come on either.
So I's say, do the A&B jumpering, then check the relay then the fan motor itself.
Sorry, don't have a schematic.
Jake
[Modified by JAKE, 6:29 PM 3/13/2004]
His fan wouldn't come on even when the coolant temp reached 242 F.
Put 12 V to the relay and still nothing; then put 12 volts directly from the battery to the wire leading to the fan, downstream of the relay and the fan came on, would run for a period of time, then suddenly cut off, only to restart again after a few minutes. All the while the engine was idling.
We checked to make sure the 12 V was still connected and it was.
He had just bought and installed a new relay too thinking the relay was the cause.
So in his case it seems like the fan motor, itself, is the problem.
When I jumpered the A&B terminals on the ALDL the fan WOULD NOT come on either.
So I's say, do the A&B jumpering, then check the relay then the fan motor itself.
Sorry, don't have a schematic.
Jake
[Modified by JAKE, 6:29 PM 3/13/2004]
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Joined: Feb 2004
Posts: 72
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From: Huntsville Alabama
Re: ECM problem (Kermach)
I have the schematic from the 93 manual. All info is based on the 93 but maybe the same type of design for the 91. For the 93, the are two common features for the fans. The B+ from the ignition goes through a common 5 amp fuse for the relay coils. and then splits at a connector (C100 for the 93). The fan ground wires go to G177 as separate wires. The ECM is common but driven from two different circuits. To test the total system, force a DTC code and both fans should come on independent of any coolant temperature or refrigerant pressure sensors.
Hope this helps,
Art
Hope this helps,
Art
Thread Starter
Intermediate
Joined: Oct 2003
Posts: 27
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From: LAUDERDALE MS
Re: ECM problem (art1217)
During system test both fan come out...
I don't know what could be wrong
Could you send me a picture of the schematic by e-mail, please
Thanks a lot
Arnaud
I don't know what could be wrong
Could you send me a picture of the schematic by e-mail, please
Thanks a lot
Arnaud
Thread Starter
Intermediate
Joined: Oct 2003
Posts: 27
Likes: 0
From: LAUDERDALE MS
Re: ECM problem (Kermach)
From the ECM to the fans everything's working
Is there any sensor grounding the ECM to make the fan come out?
Does somebody have the schematic for a 91, the one for the 93 is not exactly identical
Thanks
Is there any sensor grounding the ECM to make the fan come out?
Does somebody have the schematic for a 91, the one for the 93 is not exactly identical
Thanks
