just put a new motor in my car and the cooling fans arnt comming on so the car overheats! now if i unplug the maf it throws a code and the fans come on! and it cools down,now what should i check to figure out why the fans dont come on automatically with the maf hooked up

 

check the relays under the hood. if your in fornt of the car the relays are in the black fuse box on the right

 

i tryed the relays that didnt fix it

 

You need to put a scanner on it to see what the pcm is seeing. Since the fans come on with the SES, there is nothing wrong with the relays. Maybe your temp sensor in the water pump has issues.

 

I took out my lower temp. t-stat a few weeks ago and also used my Hypertech to put the stock fan settings back in. Few weeks ago I stopped to chat with some friends and the car was idling and it got hot enough that the check guages light came one! It runs just below 200 degrees when driving though. Guess I'll check the relays or unplug the maf and see what happens....