Have a friend with a 1985 F250 w/6.9L diesel. Starts ok when cold - and will start ok when still hot (restart a few minutes after shutting off). Problem is it won't restart if tried about 15 to 20 minutes after shutoff. If he takes truck to store to do some shopping and comes out and tries to restart about 20 minutes after he shut it off it won't restart. He has to wait at least 1 to 1 1/2 hours before it will restart.

He replaced the glo plug module but didn't fix problem. He said he checked to see if the glo plugs were getting voltage during the time period it won't restart and said they were not - so we suspect there's another temp sensor/switch somewhere in glo plug circuit that could be the culprit?? Appreciate any help or comments

Thanks,

Walt

 

I've heard this one a few times lately. Can't remember if there was an easy fix. It should still be hot enough to start without plugs so maybe it's in the electrical. Check out the wiring harness plug in on the right inner fender that goes to the engine. The two big yellow wires (glow plugs) like to burn up the plastic connector.