I swapped in an LT1 a while back and when i brought the car out of storage for the year i noticed the fans arent coming on. ever.
They dont come on with temperature, a/c, i jumped the two pins in the connector under the dash, and nothing. The fans were working last year.

When i try to turn the fans on by shorting the two pins together you can hear a click by the relay but thats it.

Where do i start?

I checked the fuses, they are fine.

 

I went out and bought a new relay and swaped it in, and no difference. I also took a volt meter and i have 12v at the power connector for the pass side fan. but the fan doesnt start, and i also switched that connector to the drivers side fan, and same result. I think it is unlikley that both fans take a crap at the same time so what else could i be over looking?

Im doing all these tests by jumping the two pins in the obd port under my dash, that has always worked to turn the fans on in the past.

I think its fair to rule out the water temp sensor, since they do not work with the obd port either.

 

are you using thirdgen fans or LT1 fans?

 

Stock tpi dual fans.

I have verified that the drivers side fan motor works, while the pass one does not. I have good grounds to both fans.

Since the driver is the primary fan and im not sure if i get good power to that plug i guess that does not eliminate the water temp sensor, and the plug i did get 12v to, had a bad fan motor.

I did plug the new motor in to the known good cable, and i didn't receive a response from the motor however.

Let me know your thoughts

 

bump

 

Just checking for reference, but do you have g8 on the c100 hooked up to the brown wires from the relay and the 2 green/white wires to hooked up to either A10 or A11 if they are hooked up to different points or A11 if they are hooked up at one point?

 

g8 is not being used...and i dont have an a10 or 11

 

So how are you controlling them with the computer? A10 and A11 on a LT1 swap is what tell the fans to turn on and off? Do you have them hooked to an external temperature switch that tells them to turn on a specific point and turn off at one? If so I had one of these and it was a POS and never worked right and caused my car overheat once on the Hot Rod Power Tour in traffic. Took it out and wired them through the computer and no problems since.

Also have you checked your grounds on the fans? If there is 12v present and the fans are not working I would check the ground. How about running a dedicated power and ground wire from the battery to the fan and verify they are both working.

 

IF, they worked last year, try shooting some wd-40 or similar product in the fan motors. perhaps there is some surface rust that collected on the fans internalls? couldnt hurt to turn them a lil with the motor off and cool. maybe you developed a dead-spot from sitting? kinda hard to believe they just died from sitting over the winter, all the sudden, if they worked when you parked it.

 

you are talking about an a10 or 11 on the c100 right? mine only goes up to a7. as far as g8, its possible i had the numbers flipped around when i looked. Is G8 the same brown wire that goes to the primary fan relay?

Anyway, i found the problem, there was a solder when i originally did the wiring that was in the process of breaking on one side, there were only 3 or 4 strands still connecting on a 16 gauge wire.

fans are working again!

 

No I was talking about A10 or A11 in the LT1 computer. Glad you got it all fixed up.