cooling fan problem

[jim homick]

hello. i am working on my sons 86 g.n. the radiator fan will not come on. i have started troubleshooting. each relay has power at the red wire. there is no power at the brown wire(s) on either relay. any suggestions? thanks in advance, jim

 

[mikestertwo]

Check your A/C fuse.

 

[jretrodude]

I had similar issues with mine too!

Is the car at operating temp for the fan to come on? Should be like 197 or something that like? Also try swapping chips, I had an old 1990 pitbull chip in my computer that always made the low speed fan run, spent money on high and low relays and got new pigtails, and it was all because of the chip. I put a stocker back in there and it comes on when it's supposed to now instead of running at low speed constantly. Hope this helped ya.

 

[garyk1970]

the brown only has power when the ign is ON.......turn car on then inject ground on the green wire to check relay,wiring to fans and the fans themselves......
if good check the temp sending unit(s)

 

[jim homick]

hello. thanks for replying. i am checking the brown with the key on-nothing

 

[jim homick]

also, we let the car warm up till the gauge indicates about 205 degrees and nothing. once the motor is shut off, the fan comes on. thanks again, jim

 

[garyk1970]

also, we let the car warm up till the gauge indicates about 205 degrees and nothing. once the motor is shut off, the fan comes on. thanks again, jim

if the brown wire has no + voltage with car on,its your problem.......wiggle the main harness/plug in the engine bay at the firewall under the brake booster/wiper motor.....you most likely have a open there....washed the engine lately??!!

 

[GNVenom]

Do you have the powermaster? Does the power brake unit work?

The brown wire is shared by the powermaster relay, so if you have power brakes but no fan, it's a wiring problem.

 

[jim homick]

funny, but i just replaced the power master with vacuum brakes because it has failed. if there is a powermaster relay, where is it? we just got this car so i am not familiar with it. thanks for replying, jim

 

[w4625]

Vortex Turbo Buick Performance then go to troubleshooting then to fan circuitry.

 

[jim homick]

thanks for replying. i have begun troubleshooting. i got to the point of testing the brown wire for 12 volts. it was dead. i have checked all fuses in the fuse panel and all were fine. ideas? thanks in advance, jim

 

[jim homick]

the other thing i just remembered is that when we got the car, the fan would come on when you turned the ac on, and now it doesnt. the only thing i've done is taken out a vdo electric water temp gauge and replaced it with a mechanical auto meter gauge. anybody?

 

[IrvJr]

You may have disconnected the sensor that feeds the puter for the fans. One of the 3 coolant sensors is for the fans, not sure which one.

 

[bmackinnon]

Check your A/C fuse.

hello. thanks for replying. i am checking the brown with the key on-nothing

thanks for replying. i have begun troubleshooting. i got to the point of testing the brown wire for 12 volts. it was dead. i have checked all fuses in the fuse panel and all were fine. ideas? thanks in advance, jim

I had this problem also.... except mine wasn't applying the ground signal on the wire from the ecm. Troubleshot it with the GM Service manual, vortex site, here, there, and everywhere.... I, too, checked all my fuses..... after about 9 months of fighting this thing, I found another spot in my service manual detailing fan troubleshooting (there are 3 different sections in the manual that deal w/ the fan! ) that told had me check the A/C fuse.... found it blown, replaced it, and the fan works perfect.... just sayin', it's probably something simple... re-check the fuses, even the ones you think wouldn't have anything to do with the fan.....