Hi there, first post but have been lurking a while. My damn 1985 F250 6.9 IDI has decided to not start, no power to anything. The break lights work when you press the breaks but headlights and all don’t. The starter turns over when you jump it at the relay but of course it won’t run.

I had this problem a couple months ago as well. Parked at my friends house in the same exact spot and it wouldn’t start then. Got into it trying all sorts of things replaced the glowplug and starter relay, replaced the ignition switch, even replaced the tumbler. Funny thing was nothing worked then on about day 4 of it sitting there a roomate of my friend texted saying I left my lights on. I scurried over and the damn thing started. I just put the light switch on just in case a miracle happens again. This hasn’t happened elsewhere, I’ve had 99 other problems but that ain’t one! Any ideas? I’m not a mechanic but have had to learn a lot over the past few years. Electrical is not my strong area. Checked all the fuses. There is power at the fuse box. I’m ready to sell…

I’ve got another 1985 F250 6.9 IDI, in better shape but no title with an air leak in the fuel that I haven’t hunted down. It’s my parts truck. I’m in Olympia WA.

 

Have you checked power connections?
it sounds like there is a bad connection on battery, bad cable, or bad connection on other end of the cables