My fan keeps running when I start truck. In InSite data monitor it says AIR is commanding it. When I shut AC switch off in parameters and start truck....the fan is off.
So I put it back to ON in parameters...unplugged the connector and used a paperclip and waited a few minutes....wouldn't shut off.
I used my test light and had full light power on one pin...tried the second pin and it had dim light power. When I leave the grounded test light on that (dim pin)...it will shut off the fan. As soon as I pull it away...the fan starts again.
I assume there's not supposed to be voltage on both pins?
This started after getting a shop to fix my erratic coolant alarm. That seems good now but I have this problem instead lol
AC switch/wiring keeping fan running
Discussion in 'Heavy Duty Diesel Truck Mechanics Forum' started by skman, May 16, 2024.