scccooter

Ok...here is my problem. Occasionally (well about 25%) of the time I will go to start the truck and I get nothing. The starter does not crank at all. So far, I have changed out the battery, the ignition fuse and solenoid relay in the fuse box. (oh...this is a 2004 F150). If I go to the engine compartment and unhook the connector with the yellow/blue wire and use a bypass wire and touch it to the positive battery terminal....the starter cranks...so I assume the starter is not the problem. When I perform this with the key in the run position...the engine will still not start even though the starter cranks. Now...I am at a loss as to what my next step would be in diagnosing the problem...MY instincts would say it is the ignition switch..but when I turn the key...I do here the relay in the fuse box click.......Does anybody have any Idea whatsoever what I can try next???

Thank you!!........Scott

scccooter

This must be a tough one!! I for one am totally stumped!

colevig

Just for sh*ts and giggles go under and hit the starter and solenoid with something hard and not metal. I had this same problem and thought the same thing but it was actually the starter. If it's not that then at least you ruled it out.

scccooter

Thank you for responding!! I ruled out the starter when I connected the Yellow/blue wire running to the starter solenoid directly to the + battery terminal...it cranked when I did that. But...it should also have started if I had the key in the run position but it did not......so....I am still way stumped!! And now it doesn't start/crank at all when I turn the key!
Thanks again!!
Scott

alsatropine

iTrader: (2)

Scott, do you live up north? Have you looked at your fpdm? It's located under the spare tire mounted to the frame. Remove it and check for corrosion. These have been known to cause all kinds of crazy problems.

Lizardking419

I had an intermittent start problem on my 2001 F150. I would turn the key forward and it would not do anything. It would start fine 10 times in a row and then do the same thing. I ended up changing out the starter and it fixed my problem. There must have been a dead spot in it. This may or may not help you but I know how frustrating it is when you get in the truck to go to work and it won't start. Good luck.

colevig

What exactly is the fdpm?

Lizardking419

Fuel Pump Driver Module.

Marc D

Don't forget the KEY. Our trucks utilize a chip in the key that can go bad. If you have another key try it. If not the key, drop the spare tire and look at the FPDM mounted on the frame rail cross bar, like Lizardking419 suggested. This is a very common part that fails.

scccooter

Thank you for your responses. I broke down and had it towed to the dealer garage. It turned out to be something in the wiring junction box!