https://www.ford-trucks.com/forums/4...ke-thread.html


Welcome, I assume by the date of the thread you replied too, you were searching for the answer.

I think you saying it spins over but will not fire off. If that is the case, click on the link, it will tell how to check the glow plug relay etc. Also, if you buy the napa gpr 109 it will save you $$$. On the 3rd page of that link, there is a picture of the gpr location posted by springer pop.https://www.ford-trucks.com/forums/4...ke-thread.html

There are two relay right in the middle of the engine next to fuel filter housing. The front one is the air intake heater and not needed. The farther one back is the glow plug relay. I would recommend disconnecting your battery while changing it to avoid blowing fusible link as the big terminals always have power. While you are at it, clean your battery terminals really well with a wire battery brush.

 

Glow plug relay



Napa sells the replacement GPR110 model, or you can ask for the 109 model for half the price. The only difference is the mounting tabs are rotated 90 deg., but you can make it work.