I will just say thaT I have had to replace the ignition switches in all of my vehicles except the 1994's I've had.

I got to the point where if the problem somewhat indicated the ignition switch and there was 200,000 or so miles on the vehicle I would just change the ignition switch - with a GM or AC Delco.

I did do a fair amount of diagnostics to rule out the usual suspects before changing the switch.

Every time I changed the ignition switch, it cured my problem. I've changed 5 ignition switches. All at around 200,000 miles.

I would say age and miles driven at the hit of the key would have more to do with things than the actual miles on the vehicle

 

Depending on where you are checking the glow plug system, things will go to ground. If you check a glow plug wire and any of the glow plugs are plugged in the wire will show it is grounded.

Glow plugs are grounded and all the wire get tied together at the controller

 

I've been at a standstill for a while due to money but hopefully soon I'll get some new batteries and clean my 3 passenger side ecu and any other grounds I can find with brake cleaner, a wire brush and electrical contact goop. A new acdelco ignition too.

I've been doing a lot of reading on here along with the helpful posts in this thread.

Knowing that the ecu will power down at the first sign of trouble is really helpful. Thanks guys, I'm tired of my nice and first diesel truck just being a lawn ornament!