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EFANS...Problem

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Old Mar 13, 2011 | 10:03 AM
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Default EFANS...Problem

Anyone ever see an issue were the EFANS are constantly on? I get a ground signal from pin 42 even with the key on engine off!! Im going to try swapping the PCM here in a minute to see if that changes but any advice would be greatly appreciated.

Thanks
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Old Mar 13, 2011 | 10:36 AM
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Update: 4 different PCM's all with the same result...KOEO 42 ground solid. Its not waiting for the "Fan on" time to ground 42
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Old Mar 13, 2011 | 10:47 AM
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Oh btw here's what I've been through so far to check this issue:

1: High Pressure switch on the A/C... thinking this is the culprit but not sure. I was told that if I disconnect the connection though it should turn the fans off and that will let me know if it is or isnt the problem. Well I disconnected it and the fans still stay on. Im juggling the thought of if the switch is disconnected, does the PCM treat this switch as if it was simply faulty? What i mean is even though i took the connection off the switch, the PCM will still look at it as a faulty or non responsive switch and kick the fans on, correct???

2: Checked with three different PCM's and they all result in the same thing. Key on ignition on OR off pin 42 has a constant ground signal instead of waiting for the on temps.

3: Removed the fan wiring harness completely from the equation and have been testing the wire that is in the 42/blue slot so that im not getting conflicting data from a possible faulty relay

What else could I be missing!? Does anyone know if the A/C pressure switch could be the issue even though i have it disconnected? I mean should it turn the fans off or would it simply keep them on and treat a "Non connected Switch" the same as a "Faulty or Bad" switch!?

Thanks fellas
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Old Mar 13, 2011 | 11:06 AM
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Sounds like 42 found its own ground somewhere. Are you using 85 & 86 on the relay coil?

see the .pdf
Attached Files
File Type: pdf
Fans .pdf (40.4 KB, 112 views)
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Old Mar 14, 2011 | 10:25 AM
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If you aren't actually TESTING with relays, you are most likely misunderstanding what your DMM is telling you:

https://ls1tech.com/forums/14560622-post10.html
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