Faults:

Water pump - 450,000 km.

Alternator - 390,000 km.

Bad ground connection - cut out wipers - 360,000 km.

Frame rot - 440,000 km.

Broken wire in rear door - caused seat-belt, brake, & engine light to go on - 380,000 km.

Passlock malfunction - 410,000 km.

General Comments:

I absolutely love this truck. This is the first time I've had anything but a Toyota or Nissan, and I was very skeptical of it at first. I bought it incredibly cheap with very high miles, hoping I could cobble it together enough to pass a safety and use it for an occasional farm beater for a while. Three years later it's still my daily driver, and I've abused the holy heck out of it.

I got it cheap because the previous owner had several lights come on (brake warning, seat-belt, engine, vehicle lock) and the wipers wouldn't work on their intermittent function. The dealer told him he needed a whole new wiring harness, and several sensors.

A few quick google searches showed that a common problem causing the warning light issues was a broken wire in the rear (extended cab) door - right where it enters the door. Sure enough, this was the problem. 10 minutes with a soldering iron and some heat-shrink and this was good. The stock wire is just a tad too short to handle repeated flexing, so I extended it a few inches when I fixed it.

The wipers are (apparently) a common problem as well. This is often mis-diagnosed as the Body Control Module (BCM), but I'm told it's almost always a poor ground connection. There are two ground 'blocks' on this car - one on the driver's side by the master cylinder, and one on the passenger side. All the wires that require grounding are mated together in these blocks. These aren't designed too well, and sometimes a ground connection gets loose/corroded. A little clean-up of the connections fixes them (a little bit of a pain on the driver's side, as the master-cylinder prevents easy access). This is the only major design 'problem' I've had with the car, and compared to my last Toyota (which had a known problem of the flywheel pilot bearings exploding and taking out the bellhousing) it was pretty minor.

There's a known problem with these trucks where the vehicle electronic 'passlock' system malfunctions and doesn't let the vehicle start. Obviously quite a problem, but it's a pretty easy fix: Lots of tutorials online explain how to snip a wire beneath the steering wheel and disable the passlock system.

The alternator went out at about 380k, which seems to be about when all my alternators/starters wear out regardless of make, so I consider this normal. It's still on the original clutch (somehow), which I'm very impressed with. Similarly with the water pump went at 450k, which is about how long my water pumps typically last. I was rather impressed as my brother was driving when the pump went. He was too foolish to pull over when he noticed an issue, so it drove about 15 km puking out coolant and overheating. I thought he must have warped the head or done some other major damage, but didn't seem to cause any lasting problem.

This is my daily driver, but I've used it to haul loads far in excess of what any sensible person would haul with a 4-banger 1/4 ton. Towed a round baler 120 km, several hay & grain wagons around the county, a couple full-sized sawmills, towed a haybine 80 km and a disc mower 300 km. Hauled two loaded tractor tires (1,400# combined) in the box when I was in a bind one time and didn't have a trailer. It took this all in stride.

The most major problem I've had to fix was frame rot. These frames are pretty good compared to some, and I've always had mine rust-proofed. Even so, there's a spot right behind the cab by the front leaf-spring mount that has a 'dip' in it, and this is a common area to rust through as water/salt sits in the dip. Mine rusted through completely on the driver's side. Luckily I have access to a plasma table at work, so I drew some parts up and had pieces custom made for this area; I cut out the rot and boxed the frame in. It's been rock-solid ever since. I also made sure to drill small drain holes in these regions. The rest of the frame is still rock-solid.

The only other complaint I'd have is the interior design. Every GM product I've dealt with (from my 1970's grain trucks, to my grandfather's '88 boat-car, to my mother's old Saturn, to this truck) have had the same issues; vent grills that are made of some type of cheap polystyrene plastic that swells and doesn't seizes so you can't adjust, window crank mechanisms that get sloppy and break when the window gets cockeyed due to the slop, weak door-handles/E-brake release levers that break if you don't treat them with kid gloves, etc. Not sure why they can't figure these things out. These are pretty small potatoes, however, so I can't complain too much.