Hello everyone,

I am hoping that someone can give some suggestions about tracking down my problem, maybe some troubleshooting guidelines. I have the Haynes manual, but it doesn't really mention this issue

I have a 1999 F250 7.3 4X4 withe the manual 6 speed transmission that I recently purchased. It was shipped from Arizona and worked fine the first 3 or so days. I live in Louisiana, so obviously there is a lot more rain here.

Suddenly, I start the truck like normal and later try to turn if off and the engine keeps running. The radio and the dash panel lights do go off when I turn the key to the off position, but the truck keeps running. I was able to kill the truck by pulling the #30 30amp fuse under the dash.

I have read the previous form posts about similar issues, and have replace my windshield and fuse box and gem as usually suggested when this problem occurs, since we get plenty of rain here, it made sense that a few days here and it starts having the issue. As soon as I put in the replacement fuse box and GEM it starts fine, and also does not turn off again.

Details:
--The fuse that I pulled to stop the truck had the following description in the user manual: "PCM relay coil, ignition coil(gasoline only), Fuel heater(diesel only), Waste gate solenoid(diesel only), injector driver module relay coil(diesel only)."
--if i connect the batterys, replace fuse #30, I hear relays clicking and the dash ABS, Wait to Start, and Door warning lights are on. With no key in the ignition.
-- To attempt to test the ignition switch, while it was running, I disconnected the two halves of the plastic ignition switch under the steering wheel. The truck did not turn off. Maybe this is not a good test, but I assumed taking if apart would break the connection and turn it off.
--The have let it sit for about a week after replacing the windshield and it there is no change. When I replaced the GEM and Fuse box they were still covered with dust and did not look wet.
--It looks like there was some previous remote start from the previous owner, but nothing wired in now, and it worked fine for about 5 days.
--I have gone through all relays in under-hood and under-dash boxes, they all click, but have to go through again and test resistance this weekend.

I am now suspecting some of the solenoids (wastegate, starter...) or maybe the PCM, but money was already tight, so I really want to stop throwing parts at the problem, and find a cause before purchasing any other replacements.

Thank you all in advance,

 

You may have already found the link below in your search - this guy said his issue was a bad brake pedal sensor

http://www.thedieselstop.com/forums/f24/truck-won-t-turn-off-268209/#/topics/268209?page=3&_k=dsoo1f

 

There's a tiny roll pin that falls out inside the steering column on these trucks. It's on the ignition switch rod that runs from the key cylinder to the electrical portion of the switch. The roll pin allows it to pivot when you tilt the wheel. If the pin falls out you can crank the truck because the two pieces push against each other, but the missing pin won't pull the switch back to the off position.

It's a really common problem and there are several write ups online how to fix it but the steering column has to be removed and disassembled to fix it. You usually just locktite the pin back in place. That sounds like what is wrong with yours.

 

--Hey thank you, I have been digging, but did not see this forum post one yet. My truck is a manual, so not sure if that would make this not apply. But as soon as I get hope, all the pedals and plugs will be a good inspection as mentioned in that article.

 

Thank you as well, also another option, I haven't seen mentioned, and I was messing with the tilt when I first got the truck. Quick question: I can confirm the key can be moved all the way back to the ACC position, would that be a way of testing if the pin is there?

 

Start by removing fuse 30. With the key in RUN, check if you have +12v on both pins that the fuse would have plugged into. You should only have 12v on 1 side. If you have 12v on both sides, then your PCM DIODE is bad or you have a wiring short somewhere. Now, turn off ignition and then you should not have any voltage on either side. If you still have +12v on 1 side, then you should look at your ignition switch or wiring short to 12v.

If you remove the ignition switch from the column, you can slide the pin by hand to confirm operation of the switch. If you can start and shut off your engine by hand sliding the switch pin, then you probably have a column problem.

 

I gave this a little more thought. Based on these 3 statements you made, I think your problem is with the previous remote start wiring. Fuse 30 should only have +12v in run & start ignition positions. When you unplugged the ignition switch, it would have cut power to fuse 30. I would start looking at all the non oem wiring that was installed for the previous remote start to see if somewhere there is still a wire connecting the +12v to the circuit when ignition is off. Concentrate on the harness between the central fuse box and the ignition switch connector.

The previous remote start would have bypassed the ignition switch, so I think this is where to start.

 

Thank you so much everyone, your knowledge and experience is exactly what I needed.

So, just like Erikkloss mentioned in the last post, I think we can blame this on the previously connected auto start, and the creative wiring there.


Fuse #2 in the under the hood power distribution box when in place, leaves a wire hot that allows the engine to run. Take the fuse out, and there are no problems. Now, Fuse #2 is labeled air bag control module, so, I am curious to see if that has been rewired somewhere else. Custom wiring jobs are really the gift that keeps on giving...

Thanks again everyone, Couldn't have tracked it down without you all.
Ringo