Hi -
Its been a while since I posted, busy year with new job, move to Ohio, etc.

What brings me here is that when working on my 93 SSE, I noticed the radiator fans weren't coming on. I found the big 40 amp MAXIFUSE blown. I replaced it and it blew again.

I did a search on fan problems here, but the posts I found didn't deal with blown fuses but the fans not turning on when they should, usually low speed.

Could someone please verify that I'm correct in these things I read from my searches:

- Both fans spin together, either high or low speed
- Both fans spin at high speed when the A/C is turned on - does this include the defroster?? Use it alot in the winter.
- Thermistor on LH side tells pcm when to go to high speed. Should read 4.4K ohms at room temperature
- Fan motor should read 15-20 ohms

I did notice that the LH side fan was winding down, but the RH fan was not when I blew the second fuse. This will be the first place I look tomorrow when I work on her. Any insight as to where I might find the short would be greatly appreciated.

Thanks in advance and Happy New Year to all.

You could unplug the fans and jump the relays. If the fuse does not blow at this time, then one of your fans is bad. Also try to feel for play in the fan shaft by rocking the top of the fan blade toward the front and back of the car.

I think the right hand fan is the low speed and spins full speed when low is on, the left is high speed and spins at low speed when low is on and high speed when high is on.

Beings the left was spinning down and the right was stopped, I would suspect the right fan may be shorted. Can you unplug just the right fan and retest? Does the right fan spin by hand or is it locked up?

Both fans spin by hand. But I only saw the big LH spin before the fuse blew again. Thats why I think the RH fan may be bad. How do you jump the relay?? I will look tomorrow to see if I can unplug the RH fan and try again. I bought a couple more fuses today to troubleshoot with. But at $2 a fuse, I want to find out quick whats wrong!!

How about disconnecting each of the fans and checking resistance on the wires through the fans and to ground and to the relay. Could save replacing fuses... I don't have a circuit diagram of that year but I assume there are connectors near the fans to enable replacement. There was on an 89 Century with a dead fan.

I believe I used a fused wire directly to the battery to test the fan.

Try putting the fuse in with both fans unplugged. If the fuse doesn't blow you'll know that it'* not a short in any of the relays or wiring up to the fans. Then plug in one fan at a time.

Ted, this will work if the relays are jumped. That'* why I suggested it. But if the relays are not jumped then there is no power being sent to the fans. You could also NOT jump the relays and let the engine run until the PCM turns the fans on, but without a scan tool you have no way of knowing when or if the PCM commanded the fans on.

I think Ted'* idea would be ok... I could force the fans on by turning on the A/C or the defroster, right???

Now that'* thinkin'!

Yes, I think that should work. The A/C should command the fans on. The rear defroster has no effect on the fans...maybe you are refering to the front defrost as the A/C runs with that too?

IMHO, I believe a fuse should be used as a last resort safety device, Not as a diagnostic tool. A DMM should be used in this case.