Fan Issues, Coolant sensor?

[98hd]

My fans have not been working. Finally started digging into the problem, and the PCM is not grounding the signal wire to turn on the fans. Could the coolant sensor be bad? I tried unplugging it while running and the engine died. I imagine if it was completely bad the engine wouldn't even run.

Any ideas?

I have a nelson engine harness, fan harness, and tune.

If I hook a test light to the neg batt, and touch the pin coming out of the ECM plug for the fan, they turn on. So it must be something with the sensor or the ECM. It used to work just fine.

[skeet]

the fans turned on in the PCM? is the pin all the way in the pcm = making proper contact!! sounds like youre not getting a pcm signal or its not mating to the contacts in the pcm

[98hd]

the fans turned on in the PCM? is the pin all the way in the pcm = making proper contact!! sounds like youre not getting a pcm signal or its not mating to the contacts in the pcm

I can check it this weekend to see if the pin is in there, but I did try pushing it in further and pulling to make sure it was seated well. It has worked fine for almost a year (although I rarely have driven it).