Fans won't come on

[Alik]

I can trigger the fans by grounding some of the wires near the ABS unit, so, the fans themselves are out of the question.
Shorting the rad sensor makes the fan relay click, so, the sensor is working.

Turning the A/C on leaves both fans lifeless.

Please, help. I'm stumped.

 

[95'RS-T]

bad relay?

 

[Alik]

Not according to my mechanic, but, he's not God.
Funny enough, everything was working fine until I swapped the alternator without disconnecting the battery, and sparked the old POS to the rad.

Since then, no fans (unless manually jumped).

 

[rstchris]

Pull the relay and probe the 4 pins with the ac on. (ac must work properly) you should have 2gnds and 2+. If not look at what pin is not doing it's job and dig into a wiring diagram. If all 4 pins check out good then restore gnd or relay/fused+ to the fan.

 

[Alik]

The A/C has never worked well, but, now, not even the fans will come on.
Not quite sure what you mean by "restore gnd or relay/fused+ to the fan"
could you explain it to me like I'm a five-year old, please? (not screwing with you).

 

[rstchris]

There is a chasis gnd always hooked up to the fans(or should be) and bat+ from the batt through the fan fuse and to the Low speed fan relay all the time. When you turn the key on you should also see B+ to the relay coil. Then when the ecu wants to make the fan come on (hot engine or ac request) it sends gnd to the fan relay coil. Then B+ is sent through the relay to the fan making it come on. If you unplug the coolant temp sensor you should feel the relay click while the car is running. If it does then there is an "open" on the fans gnd or B+ from the fan to the relay. If it does not click on then there is an "open" in either of the relay coil wires. Check fuses first.

 

[Alik]

Thanks, Chris!
I've already checked the fuses.
I'll play with the rest tomorrow.