Help w/ Temp Fan Light on '85 Deville

MSUC5Vette · #1 (**permalink**) 11-22-08, 10:19 PM

The temp fan light on my '85 4100 V8 Sedan Deville is coming on pretty much as soon as the car is started.

The fans are not coming on. I don't drive it enough to figure out if they come on eventually, but I would like to figure out what is causing the problem. I definitely don't want to over heat it.

Is there a standard test procedure for tracking down the issue?

I tried searching this forum, but 5 searches has resulted in 0 posts. Is there a trick to searching on this forum?

Dave S Texas · #2 (**permalink**) 11-23-08, 12:31 AM

First of all....is E14/E15 code showing in diagnostics? What codes are showing, besides those?
The fan control module(FCM) is sometimes at fault. It is located behind the headlight assembly on the LH(drivers) side.
There are two grounds to check/clean/tighten, both on the block in front of the starter. Also check the Blk wire between the FCM and Ground for continuity. Check the fusible-link/check the Red/White wire between the F-L and the FCM.
Of course you need to check each fan to make sure each works with a 12v supply.

MSUC5Vette · #3 (**permalink**) 11-25-08, 09:59 PM

Thanks!

I will test those things out this weekend.

The headlight has to come out to gain access?

Dave S Texas · #4 (**permalink**) 11-26-08, 07:58 AM

The headlight bucket has to come off for access to the FCM.