My cooling fan just up and quit working? Doesn't even come on when I jump A&B to check for codes. Where would you guys begin in in diagnosing this problem? I've search on here but no luck.

Also it's an 86 IROC 5.0 TPI with a single fan set up.

Thanks!

 

Start at the motor; verify that there's 12V across its plug when the fan should be running, with the plug plugged in.

If there is, you need a motor.

If not, go to the relay. See if it clicks when the key is on and you ground the temp switch in the pass side head. Also verify that under the above circumstances, the black wire is within a couple of tenths of a volt from ground.

If it does, check the blk/red wire to see if there's 12V there.

If there is, your problem is the black/red wire.

If there's not, check for 12V at the red wire.

If there's voltage there but not at the blk/red with the relay clicked, the relay is bad.

If there's no voltage there, follow it back toward battery until you find where the 12V goes away.

 

LOL! Kids today!


It is a DC Electric Cooling Fan... NO ELECTRONICS!

 

The '89 single fan set up is ECM controlled (yes, electronics). Pin C1 goes low to activate the cooling fan relay.

With the key-on, engine-off you can ground C1 at the ECM and the fan should run. If not then the relay may be bad or the C-H FAN fuse may be bad.

RBob.

 

'Looks like we're talking about a '86 here...

 

Just a typo, what I described is actually for an '86. The fan is ECM controlled via the fan relay. The wire from pin C1 is DRK-GRN/WHT.


RBob.

 

Thanks for the non smart-*** answer Rob...I will look into both your's and Sofa's suggestions..

 

Thanks Sofa, where is that relay located?

 

Firewall near brake booster. Identify it by wire colors. RBob's schematic is very helpful in many ways even if not strictly applicable.

 

If the fan relay isn't near the brake booster, check the radiator support on the passenger side. IIRC, some of the early f-body's had them there. GM did have their fun with various relay, sensor locations, and wiring for same...

As Sofa mentioned, check wire colors on the relay socket. They should help to locate the right relay. Although after so many years the colors tend to fade and change.

RBob.

 

Thanks guys, I'm going to try to get at it this weekend. I'm dying to drive her but not if it's going to overheat,,

 

The diagram shows a fusible link. does anyone know where that might be found? I have replaced the motor and relay and it's still not working.??

 

Iirc fusiable link is next to the battery, is that where your loosing power ?