Jstarr

This random failure came out of nowhere, but also coincided with reduced AC cooling. I just replaced with fan control module (albeit with a used unit) to no avail. I’m planning to check the 80a fuse this evening, but I’m curious to know if anyone has experienced a similar failure of both fans simultaneously. Both fans spin freely with no obstruction and look to be in excellent condition. Looking for some help if this fuse isn’t blown. I’ve done countless searches here and via google with no luck other than where I’m at now.

Jstarr

Checked the fuse. No issue there. I’m thinking maybe the used control module is faulty. Noted the right fan spinning slowly for a brief moment then it went off. AC blows super cold at normal driving speeds, but goes warm at idle… coolant temp holds steady at 175 until stopped, then slowly starts to rise as the AC warms up. If I leave the AC off, temps hold steady at 175 with regular driving in the 90 degree temps here in SC.

jchapura

If both fans suddenly simultaneously started acting wonky then its probably an issue with a common point in their electrical path. I'm pretty sure I've read recently that the front fan control module does not need re-coding so buying another one doesn't entail additional programming expense.

Jstarr

Thanks. As mentioned, I replaced with a used unit, but no guarantees that it’s good. Looking at the diagrams, I do see that it has a feed from the front control module. Looking to pull some codes with a Foxwell tomorrow.

jchapura

It would interesting to learn if one can temporarily directly connect each fan to 12V to verify operation (independent of the controller).

Wayne Smith

Durametric allows you to turn them on and off independently.

Jstarr

Tried to command on the fans via Foxwell and heard the right fan come on briefly, but not repeatable. Ran 12v to each fan and both work flawlessly. Looks like both the original and the used replacement control unit are bunk. New unit on the way. Will report back.

Jstarr

Of all things, I traced out back to a loose body ground nut at the LF. The main ground for the front body control module and the fan module. Two spins of a 10mm socket fixed the problem. Check your grounds!