89 Grand Prix Cooling issues

[GrandPrixLover]

Alright, my problem seems simple enough. I have an 89' Grand Prix SE with a 2.8 liter engine. About a month ago the Cooling fan just stopped coming on. So, i replaced a few sensors, still didn't come on. I have now replaced every last sensor that activates the cooling fan and it still dosen't come on. I took it to an auto-repiar shop and they said it was the ECM, so i replaced that and it still won't turn on. Any help would be apreciated. I have checked and the fan itself works.

[GregA]

Originally Posted by GrandPrixLover

Alright, my problem seems simple enough. I have an 89' Grand Prix SE with a 2.8 liter engine. About a month ago the Cooling fan just stopped coming on. So, i replaced a few sensors, still didn't come on. I have now replaced every last sensor that activates the cooling fan and it still dosen't come on. I took it to an auto-repiar shop and they said it was the ECM, so i replaced that and it still won't turn on. Any help would be apreciated. I have checked and the fan itself works.

Welcome to the forum!

Have you checked or swapped the relay(s) that control the fan?

I believe the PCM just provides a signal (12 volts or ground) to the relay so that the fan will come on. I believe there is a fuse (or two) involved there too.

Let us know what you find.

Take Care,

[GrandPrixLover]

I have checked all the fuses and fusable links and they are all fine, im not sure where the relay's for the cooling system are. Any ideas?

[corning_d3]

Just going out on a limb here, but have you directly applied power and ground to the fan to see if it still works?

[GrandPrixLover]

Yes, i have done that and the fan works.

[corning_d3]

OK, that's good. What about the continuity of all the wiring? I'd suggest getting a diagram and a connector pinout to test all the circuits. A cheap DVOM is all you need. The only (and safest) way to is by disconnecting the ECM connector(s) before probing around. You'll probably have to anyway to test all the circuits.

[GregA]

Originally Posted by GrandPrixLover

I have checked all the fuses and fusable links and they are all fine, im not sure where the relay's for the cooling system are. Any ideas?

Relays are probably under the hood and should be labeled under the cover.

I agree with corning_d3 - its time to do a little testing of the wiring.

You can TRY to get a wiring diagram at autozone.com (try link below), but I like to have the repair manual.

http://www.autozone.com/servlet/UiBr...3d800eda79.jsp

Let us know what you find out.

Almost forgot - do you have AC in that car? And if so - does the fan come on when the AC is switched on (or the defroster)?

Take Care,

[richtazz]

There should be 2 fan relays in the underhood fuse/relay center. One is for the primary (driver's side) fan, and the other is for the aux (pass side) fan.