Jazsun

Ok guys my car overheated once in traffic because the fans never kicked on. I found a fuse which was blown in the engine bay box for the "A/P - Fan" and replaced it. That made it so the fans kicked on when I would turn the A/C on but that was it. I recently replaced my waterpump and replaced the Coolant temp sensor which is inside it. My fans still do not turn on at all. I waited until the engine got to 230-240 ish and still nothing.

What else can I do?

UPDATE: Checked all relays for fans #1,#2, and #3 all work fine.
They do not turn on when I jump the #5 and #6 cables on my OBDII port also.

Jazsun

****, thought I was in the LT1 forum, please move. srry

anasazi

check the fan relays

Jazsun

Could fan relays still be blown even if the fans turn on when the AC turns on? Is there anyway to check the relays using a voltmeter?

Jazsun

anyone?

Pneumatic_Tire

Relays dont really blow, they either stick open or closed. I'd replace all relays, check for power at the fan connectors, and if all is well there, then I'd start looking at the ecm.

anasazi

i had something similar on my old LT1 z28 but it was the opposite, the fans wouldn't turn on with the A/C but they would for normal temperatures. the guy replaced a relay and poof everything worked.

if i recall correctly you have a horn relay that is the same rating, use it to sub into the fan relays to see if its a relay problem, or put the fan relay into the horn spot and hit the horn.

Jazsun

Is there horn relay in the engine bay box? Ill have to look but I didnt see one before. I will check the relays soon. thanks

anasazi

IIRC yes, there is. although, it has been 2+ years since i've seen an LT1 fusebox.

Jazsun

Ok guys there is no horn relay, thats what I thought. There is only a fuse for the horn. There are only a few relays in there, fan relay #1,fan relay #2, fan relay #3, abs relay, ac compressor relay. Thats it. If the fans turn on when the AC turns on which relay is the AC using? how the hell can I narrow it down or test them?

If I knew which relay the AC used to turn the fans on then I would Know I had a working one and coule swamp the other two fan relays into that working one.

Also when I tried doing that jumper thing w/ the obd2 port no fans turn on.

Jazsun

no body knows?

anasazi

use the abs relay if its the same thing

Jazsun

Its not the same kind, but still doesnt help me "test" the fan relays. I really dont want to swamp relays and have to let the engine reach 240 to just test the relays 3 times, when it could be a combination of them which arnt working as well since a fuse was blown.

Pneumatic_Tire

ive just skimmed through this real quick but if you want to test a relay, get a couple jumper wires and connect one from the battery positive and the other one to a ground, negative cable or whatever, and then probe around at the terminals till you hear a click and feel the relay energize. if you cant get it to do this, its bad.

Jazsun

By terminals you mean the 4 prongs on the bottom of the relay? Do I probe w/ both the pos & neg at same time correct?