1988 F-250 4x4 460 5 speed tilt column w/ cruise control. I have eliminated the wiring at the top of the column as being the culprit. I removed the steering wheel, dropped the column, took the mid-column ignition switch off and looked for bare wiring everwhere. All connections are tight.

Here is what it is doing: with the ignition switch in the on position, if I turn the steering shaft, my entire electrical system goes dead, and the battery light stays on. With the ignition switch off, the rear antilock light stays on. There is one spot where this happens. The shaft within the column has a flat spot that keys the upper shaft into the lower shaft. This seems to correspond with the problem. There doesn't seem to be any wiring within the steering column, and the harness that runs alongside it is fine.

 

When you say your entire electrical system goes dead, do you mean it kills the engine too, or just the in cab wiring.

If its just the cab I would suggest the problem involves the turn signal switch since the problem occurs when you turn the wheel. There is a curved connector on the column for the switch (also for flashers, horn, and cruise) you can try unplugging that and seeing if the problem goes away.

Its also possible that the system is grounding itself through the turn signal because of a short or broken ground somewhere else and happens to be losing the ground when your wheel is in a certain position. If this is the case, then when you unplug the connector I mentioned you will lose that improper ground and have the problem no matter where the wheel is.

 

That was my initial thought too. That's why I removed the steering wheel, and then the entire electronics assembly below the steering wheel as a single unit (the part with the turn signal switches and horn stuff where all the wiring goes to). At this point I have every electrical/electronic component on/ in the column removed, and am turning the steering shaft with a pair of pliers on the snout of the steering shaft.

 

Ok, if I understand correctly, you have the signal assembly removed and still when you turn the shaft to a particular position it kills power?

Did you unplug the connector for the signal assembly, or just remove the mechanical part? I ask because I had my column removed and taken apart recently to replace the signal switch, ignition acutuator, key switch, and ignition switch and there aren't very many wires there. Just the ones for the turn signal, and lower on the column for the igniton switch.

The column is sleeved and there is really no way a stray wire could find its way inside to be pinched or rubbed that I can think of. The igniton switch itself has mechanical parts near where any movement occurs so isn't likely to have a wire issue.

I suppose if you had a worn/loose actuator it might twist the rod running down to the switch, and if the switch was worn you might loose contact, but thats quite a strech of the imagination, especially for it to occur in one particular spot.

Forgot to ask again, does it kill the engine too, or just in cab wiring?

But if you unbolt the igniton switch, and unplug the turn signal switch, then there will be no power at all in the column, but it should still be grounded - which I would check given the nature of the problem.

If you still have the problem with the slider removed and the signal unplugged and the column is grounded I would start looking under the hood at the column, steering box, linkage, etc..., perhaps a stray wire found its way near a moving component somehow and is shorting out, or pulling on a ground. The main wiring harness connector is in the area where the column exits the firewall, I'd start looking there for stray wires.

 

That is correct. It kills the engine too. I have stripped the column bare and am actuating the mid-column ignition switch with a screwdriver. Its still killing everything. I've already looked the entire steering system over five times looking for a bare wire or something. I've pondered chassis flex, a bad ECM ground, etc, etc. It doesent make sense because its only in one spot. I'm going to post a YouTube video of this for everyone to see.

 

Check the cab ground strap. Perhaps the cab is effectively getting grounded through the column, and at that one spot that ground is broken.
I know, it's a left-field idea, but it kinda fits the symptoms...

 

Here is the video. As far as the cab ground strap, I'll look but I don't see how that could kill everything, unless the ecm grounds to the cab.....

1988 F-250 steering column short - YouTube

 

I couldn't get the video to work, no biggy, you've explained it pretty well.

This is an extremely puzzling problem.

The computer has its own grounds right from the battery, 2 heavy black wires, I forget the tracer colors but you can't miss them.

It may pick up an external ground from the cab, but I don't think disturbing it would kill everything, but I could be wrong.

As a random thought you might try pulling the antilock fuse, its odd that it would continue to get power while nothing else does.

I would check the large yellow wire that feeds the igniton switch. It should be hot at all times. It comes off the solenoid with a fuseable link (brown or blue link) and splits into two wires before going into the ignition slider.
Backprobe or pierce it and check the voltage as you turn your steering shaft and see if it loses power.
If it does, I would make a long lead from a jumper wire and take your meter ground all the way to the battery and see if it is still losing power.

 

Ok, so,things to note. Cab ground is intact, but both the cab, frame and strap surfaces are very rusty. Gonna clean, install and paint those. The ECM grounds, you say they are at the negative battery terminal. I just replaced my battery and terminals to install a Group 31 Battery. I know they are good, but will test them anyways. Will report back. Could be a while though.

 

Bump for the morning crew. Pretty sure this is a ground issue of some sort.

 

What is the history of this truck? Was this a running truck and
this problem just occurred?

From your description it appears something is wrong with the contacts inside the ignition switch.

 

Yes it ran. No its not the ignition. Watch the video.

 

Looking at your video and the problem with the interior courtesy
lamp going on and off when you turned the steering shaft
indicates you are losing 12 volts or ground to the bulb.

With all of your problems you probably do have a bad ground
from the cab to the negative battery terminal.

Take a battery jumper cable, clip one end to the bare metal part
of the dash skeleton and the other end to the engine or negative
terminal of the battery if you can get a cable to reach.

 

I just read my last reply and it looked like I was being a jerk. If my answers are short and to the point its because I'm at work and in a hurry. Don't think me rude.