Hi guys!
My DH is sitting outside scratching his head. Our 1984 6.9 F350 dually will not turn off. Before we bought it the guy rigged up a switch for the glow plug. Before you could start the motor you would have to flip this switch about 30x to warm it up. Well, apparently this weekend the switch wore out and fell into the on position and was there over night. The glow plug relay ended up getting so hot that it burned a hole in it and broke it into 2 pieces. It also burned up wires around it. These wires have been replaced as well as the glow plug relay. The battery was dead so we charged it and jumped it and it started. I went to turn it off after we let it run for a while and the key did a full circle---ignition switch. I put it in gear and let the motor die. He replaced the ignition switch this morning. He charged the battery again. It started up. And it won't turn off. He took the steering column apart and manually activated the shut-off switch and no difference. It was replaced 30 min ago and no change.
As a side note he says that there is a fuse that was pulled when we bought it that when he plugs it in and the truck is off it shows +RPMs and goes to 0 when the truck is running.
Help!

 

There is a solinoed in the top of the pump under the top cover.
I had a 1983 that it went bad and would not turn off.
It is a easey fix.

 

Thx! We will check it out.