Looking for a way to check that the pins controlling the efans on my 1999 silverado are working correctly?

I've had the efan conversion done for years but lately the AC performance has been sucking and it looks like the fans are not working correctly. I pulled the fans today and hot wired them they both work. Also hooked them back up and grounded the pins on the conversion harness and all works correctly.

What else could it be? and how do i check the PCM with a test light or multimeter?

Also, dont have tuning software to command it through the PCM manually.

 

I have noticed here lately my ac seems to suck at times too but others it is cold as hell. Pcm with a test light is a bad idea in general, better off pulling the connector at the fam and checking voltage that way, should have 12 volts when they are commanded on, can also check the high and lo speed releays to make sure you are getti v vomtage throigh them properly when you are supposed to....

Make sure there isnt a bunch of crap between the radiator and condensor and the fins on both arent flattened, both scenarios will restrict air flow which will keep ac from performing as it should

 

I've verified the harness works correctly. Also the fans do not turn on when I press the ac button. Where do I trace that back too? Is it the pressure switch? Or just the ac controller

 

I had a similar issue, my temps were higher than normal but not so high that it was running hot or anything. Plus my AC seemed to be lagging a but. It turned out that one of the three relays went bad. Popped in a new relay and they have been working fine ever since.

 

Stupid question but are the fans turned on in the tune?