I own a 1994 F-250 with 7.3 PSD. I've had a strange electrical problem for a year or more. If you operate the turn signal/high-low beam switch, the engine will momentarily shut off. The problem is very intermittent. Sometimes it'll go for weeks without doing it then do it three times in the same day. I've pulled the switch out several times and checked all the wires for chafing and for loose plugs. I've found nothing. I haven't replaced the switch yet because I can't understand what would be wired in such a way as to kill the engine on that switch. Has anyone else ever run into this problem?

 

On an PowerStroke F250 with sporadic cut out. It turned out to be a bad fuse connection in the fuse bolck. The thing would cut out at the darnedest times, brake pedal, bump, turn wheel. I forget which fuse, either the computer or the fuel pump. the clip that makes the contact was stretched.

A couple years ago Ford had a recall on some ignition switches on 250's. You might look into that too.

Hope this helps...

Bill

 

I checked the fuse panel under the dash and found no problems there. I removed the turn sig/hazard switch from the steering column to test it. If you repeatedly flash the high beam lights, the problem will show itself intermittently. I removed the protective sleeve from the wiring bundle and checked all the wires and found nothing wrong. I wiggled both connectors and the problem didn't occur. It only happens when you operate the turn signal/ high-low beam switch handle. I've ordered a wiring diagram to help figure out how this switch is wired in. I wouldn't think that any of that wiring would cause the engine to die.


I've also noticed a few times that if I signal a lane change, the cruise control will turn off after I reset the turn signal switch. I didn't think the turn signal switch had anything to do with the cruise control wiring.

To sum it up, this has got me stumped. I guess I could just replace everything electrical in the steering column but that's not my way. I'm a mechanic by trade and I prefer to solve the problem rather than change parts till it goes away. I normally work on motorcycles but this is my truck and I'd like to fix it myself.

 

Have you checked the wires where the steering wheel tilts? also when it dies, does any of the gauges, radio, heater, still work? or do the shut off also. If everything is shutting off, I would lean more towards the ignition swtich and wiring. I haven't ever taken the ignition switch assy. apart, but if it is possible you might look for some burn't contacts, also check for some frayed wiring or shorts that might possible occuring. I'm the same way, I'd rather find the problem and fix it, rather than swap till it goes away.

 

I've taken all the plastic shrouding off of the steering column, matter of fact, it's still off. I've also taken the plastic sleeve off the wire bundle to check for breaks and worn insulation. I can find no damage to the wiring or the switch. When it does this, it's only for a very short duration. It's like someone turned the ignition switch off and back on very quickly. Most of the time, the engine never completely dies, it just rattles and vibrates and then resumes normal operation. Nothing else seems to be affected by this problem except for the cruise control. If I signal a lane change, when I reset the turn lever handle, sometimes it will turn off the cruise control causing it to disengage. I may just have to bite the bullet and replace the switch. I just don't understand why turn signal wiring, wiper control wiring, and headlight control wiring should be affecting the operation of the engine.

 

Just a W.A.G. before you start replacing stuff...

Try rigging a manual ground wire from something known to be good (not dash or lower steering column) right to the ignition switch or key. If you have a week ground ign. circuit voltage may drop when other circuits try to share it. I do not have a diag. of this, so I could be all wet...

I've seen bad grounds do all sorts of funny things to a friends F150

 

Yeah, bad grounds can cause some strange things. I'll try that. I've got a service manual and schematic ordered. When it comes in, I can trace the circuit out and see what would affect the operation of the engine. Now, I know you know this, my diesel doesn't have an ignition system per se. Whatever it is has to be affecting some of the control circuitry for the engine, but which one is the question. I've been under the hood and shook every connector I could find and not noticed the problem. I can only "make" the problem show up by messing with the turn signal handle. Oh well, thanks for the suggestions and I'll post what I find if I know what it was that solved the problem. You know sometimes you solve the problem and you don't know what you did to fix it.

 

I have a 97 psd with simular ghosts in the wiring. My cruise will kick off if I turn on the wipers, My radio will click and reset all the settings to zero while you are driving along. My wiper problem seems to be in the multi switch. These things control a lot of goodies and maybe thats you problem. Does your truck have the all in one wiper and signal switch. I am still trying to figure out my ghosts. I might have to start my own post to exersize my ghosts. I was told also to check all frame grounds.

Ed

 

Yes, my truck has the "all-in-one" type wiper, turn signal, high/low beam control handle. Mine will turn off the cruise control but it doesn't affect my radio. It will also momentarily turn off the engine when I switch from high beam lights to low beam or vise versa making the truck lurch very hard. Sometimes the same thing happens when just sitting still idling. Real Strange problem and hard to find too. I've been looking for the problem for over a year now but it shows up infrequentley and disappears for weeks at the time.

 

When you get your schematics, check to see what the GEM module is connected into, possibility that it is going out and causing the problems.

 

What is a GEM? I'm not familiar with all the abbreviations used in this format.

 

Yes I am wondering on that one too.

 

Ed
i am not going to touch the cruise/wipers/directionals problem, but i will say that your radio problem is most likely a ground problem. i would definitely check your ground connections, including at the battery. i recently installed two stereo amplifiers in my SD. i now have noise in the speakers when i use the fan or the trailer brake. i know this is most likely a ground issue as well, but my mechanic suggested another thing. he said that since the cab and motor are both rubber mounted, there sometimes can be problems with grounds in general. he suggested that i run a wire from one of my batteries to my firewall. if you do this, i would recommend a decent wire size, at least a #8 or so. good luck to everyone with the gremlins !

 

I could be wrong on the actual definition of GEM, Generic Electronic Module. Anyway, in short little black box that seems to control everything in some way or another. Basically a solid state relay box the PCM controls.

 

I have a 98 F150 4x4 with a wiper problem in the intermitten stages. If the vehicle is in park the wipers work fine. Just as soon as I put it in drive the delay (intermitten) mode doesn't work. Put it in park and it is fine again. Has anyone determined the case of the problem? Could it be the GEM?

DJ