efan problem

[bottomline2000]

It has to be the pin wire grounding out somewhere. I don't think its the a/c pressure sensor since both fans cycle on low. I would think a high reading on a/c would mean one fan would cycle on low constantly IIRC. They do cycle to high if I turn the a/c on which they are supposed to do if the truck is at op temp, but the PCM seems to not know when to activate the fans based on engine temp. If the signal from the pcm activated the fans based on engine temp then everything would work as expected. I'm pulling the computer again and checking the pin connection to see if anything could possibly be grounding there.

Thanks for the help Jenna. I'm going to figure this out.

 

[bottomline2000]

well I pulled the computer and checked. Nothing outta order. anyone have a diagram of the efan wiring harness? Also, I think I'm gonna have to have an electrician of mine check this out. getting very old. soon as my stupid post count is high enough maybe I can buy a new harness and try that since I've seen a few for sale. I want this problem gone!!

 

[Justin]

All of the harnesses are bench tested before arriving to us here for sale. I really think that it is the A/C pressure signal being sent to the PCM. I've seen one other situation in the past where a 2000 was showing the voltage equivalent of 500psi at the PCM all of the time. 210psi is the trigger for the fans to activate.

 

[bottomline2000]

Justin I sent you an email on this. How can the signal be disabled and how would this affect the a/c operation? I knew I should have had everything ready at the tune, its' just my luck I'm the exception.

 

[JennaBear]

We would just remove the A/C pressure fan condition. This would not affect the A/C use at all.

 

[bottomline2000]

ok, let me know the next steps so we can remove the fan pressure condition. I'd imagine this involves sending my PCM to you.

 

[JennaBear]

Justin will get back to you on your email.

 

[bottomline2000]

I sent Justin an email. I have found the problem.

 

[bottomline2000]

well I take that back. The relay sounded like it had rocks in it. I replaced it and still have the constant fan on condition. Problem remains....

 

[JennaBear]

This is with the new PCM in? So it stopped momentarily?