Kevin in Atlanta

I would like to test the black finned fan controller from a car I am parting out.

I have my 87 to test it on.

So far

On engine start neither fan comes on. Same for my unit.
Both fans come on with A/C button engagement. Same for my unit.

What other scenarios should I test?

Ducman82

i think you should test what temps the fans DO come on at. other than that, they sound like they are working fine

Alan

You need to provoke the difference between low speed and hgh speed (based on temp) and see that the output stage can drive both speeds - thats it. No need to test the other modes - all the logic is in the controller by the pasenger door. The final stage drivers just drive the fans. So you want to see all three drive modes both off, both half speed and both full speed - thats all.

Alan

fraggle

Easiest way to test is to disconnect the wire from the top of the AC pressure switch and turn the ignition on. Then turn on the AC. If that pressure switch is open, both fans will go full blast, even if the car isn't running.

fraggle

Oops, I was thinking about it he fan amplifier, not the controller itself. Tricking it with the signal from the AC is still a good idea, though. There is a test procedure in one of the manuals somewhere, too.