rancheroracer

Can you guys tell me where I can connect a switch to manually turn the engine cooling fans on when the truck isn't running? I did a test the other day & found the truck has a fail-safe, I pulled the #70 relay & ran the truck--with relay out fans run on high speed. Connect at sensor--wherever that is?

V8-Coyote

I'm new to the truck world. Why do you want to manually run you rad fans?

T_R

You would need to look at the wiring diagram or the case of the relay, find out which wire the PCM grounds to activate the relay and connect a switch from that to ground. But the PCM may not like that, it may think its a short and set a code or you may get a fan rationality code. Both would give you a CEL on.

T_R

Probably to cool the engine for drag racing.

rancheroracer

Yes, I wondered about that, (pcm/short), maybe with just key on-engine off if wouldn't. Have to do some checking with the multimeter I guess, just kinda scared I'll mess something up. That's why I thought I'd ask you guys.