RetroPerformanceCars

I've got a 1991 L98 C4. A few weeks back it started making a horrible noise which turned out to be the cooling fan motor being shot.

I replaced the motor but now the fan won't come on at all! I can jump the relay on the primary fan and it turns on fine but when I do the same on the secondary I get nothing. It will turn on only if i send power directly from the battery.

I checked the power supply going to the relay and there is no power reaching the plug! anybody got any ideas of what to do next? I read that there is a breaker in the relay and the circuit doesn't have a fuse, is this correct?

antfarmer2

I would think there would be a fuse

RetroPerformanceCars

Any idea where it is?

antfarmer2

On my 94 open the pass door on the side of the dash and a box right in front of the battery

Robert Perkins

Do you have power on pin E of the secondary fan relay? if no fuseable like is open if yes manually place a ground on pin F of the cooling relay does fan run if no relay is bad. If yes check continuity between pin f of relay and pin B11 of ECM. The ground is provide in the ECM.

TA

I would check the fusible links below the battery. The drain from the windshield cowl sends water right to this area and they can corrode over time. I had to replace the fusible link for one of the fans on my 91.

RetroPerformanceCars

So I'm pretty sure I've found the problem. One of the fusible links was burnt out, I checked the continuity between the burnt link and the fan relay plug and there was continuity. I'm guessing the old fan motor caused it to burn out.

My question now is how do I fix it. The wire has a black plastic joint where the link wire meets the standard wire, the black plastic joint has 20 stamped on it. Does the 20 mean I need to find a replacement 20 gauge fusible link wire or does the 20 refer to something else? I'm not too clued up on wiring.

thanks for the help guys

Churchkey

You have/need a 20 amp fuse link.

Connect with crimp connectors or slide shrink wrap over the wire, solder the joints, heat the shrink wrap @ the joint to insulate the joint.