I have a 98 expy that I parked 2 days ago and now it wont turn over. The battery is fully charged, the only thing odd is sometimes when I turn the key the doors auto-lock like when its put in gear after starting. When I turn the key the dash lights come on and look normal, when I trun it all the way to start I just hear a light tunk sound under the dash (like a big relay maybe). Could this be some type of sensor or computer glicth I can reset? This truck has always started everytime and runs great, the alt and starter are new in the last 6 months so I'm assuming its an electrical gremlin but not sure where to look or how to go bout troubleshooting it.

 

i have 98 expl also the motor is locked up but you can take a ratchet with a 3/4 socket and turn the harm balancer to make sure the motor is not locked up.

 

I'd lay odds that the big red wire on the starter is loose or your battery connections are dirty.

 

Take a look at this. Good luck!

https://www.ford-trucks.com/forums/6...ml#post5251804

 

That red wire may be all together rotted away too. I had to replace mine not long ago because it corroded at the positive terminal for the starter. Unfortunately the brainiacs at ford don't leave ANY length to the cable and there's not much of a prayer of soldering a new terminal on. I'd have to attribute part of it to the new magic salt and liquid calcium they treat the roads with here in CT now that we're all going ''salt free'' in the winters.....

If it is the red cables, its a $60 part. Bad news is its like a 1.6 hour install. I had the dealership do it due to time constraints, but you could probably do it on your own if you're patienr.

NB: It took the ford mechanic 2.5 hours, so I made out on the deal, because they can only charge you the ''book rate'' of hours !