There are generally 3 coolant temp sensors to distinguish between. A. One is for the idiot light should have only one wire B. One is for the computer C. One is for the gage if equipped. When everything is working properly the sensor I called "B" tells the computer (ECM) how hot the engine is. When the ECM sees that the engine is at 210 (or something) it grounds a wire coming from the Cooling Fan Relay, thus energizing the cooling fan.
So, things that can go wrong are: Bad fan motor, bad relay, wiring prob, ECM problem.
GW
Mulatz wrote:
I have an 89 Sunbird with the turbo. I think a head gasket has went on it
> (hoping its not the water cooled turbo again). There is anitfreeze in the
> exhaust, not alot but enough that you can smeel it and see some
> condensation.
>
> It think the whole issue started with the electric fan not working properly.
> At raod speed you don't notice it because the air flow is usually enough to
> keep things cool. When in traffic, however the fan did not seem to be
> kicking in when I thought it should. What are possible causes of this? Is
> there a sensor I should be looking at, or a control switch?
>
> Also I have to change this head gasket. What should I look out for? I know I
> need new bolts because the head is aluminum.
>
> I intend to get the haynes manual as soon as I find it.
>
> Thanks,
>
> Kirk