My 07 1500 Classic 4.8 radiator cooling fans have been constantly running on high speed. When I start my truck and put the truck in drive the radiator cooling fans will kick into high speed after about 30 secs or so and will run at high speed until I turn the truck off or let the truck idle for a minute or so.
I have replaced the coolant sensor - no luck
Pulled the PCM and checked the pin - clean
Quick tested the fan relays (no meter available) - Relays click over
Besides testing the relays for continuity I am at a loss. Does anyone have an idea of what the problem might be?
Thank you in advance!