Still getting that 500 error... so I'm putting the update here.
Update with full description:
Bought this about 7 years ago. It had 106k on the odometer, currently is a bit shy of 175k. It was a rolling office for Halliburton - you can occasionally see the shadow of where the stickers were on the driver door if the sun hits it just right.
Engine and drivetrain: Stock 7.3. I've never chipped it, and based on previous owner, going to guess it was never chipped. Leaks a little oil, but seems to stabilize around 1 quart low. I just keep a quart on hand for when I'm driving longer distances. Transmission has a sticker on it indicating that it was rebuilt at some point. Was there when I bought it. This past summer I had it serviced and also had a Moroso oil pan (larger capacity) put on using their one piece gasket. Axles are Dana 60s front and rear. I believe they are 4.11 ratio and that the rear has a lsd of some sort. Front end has been gone through in past 15k miles - all new bushings and whatnot. Front also has been relieved of the vacuum hubs. Running MileMarker lockouts using a conversion kit from Solid Axle. It's all rebuildable with off-the-shelf older vintage parts. Tires are 285/75R16 and have about 2/3 tread left. No rubbing on fenders, but does kiss the running boards when turned and compressed.
Interior: As stated, was a rolling office, had a desk from front to back along driver side with 3 computer stations and swivel chairs. Tore all that out and acquired a 12 passenger interior. Seats are in generally good shape, but some of the buckles (seat side) don't work - all body sides of belts are fine. Benches are all gray fabric. Fronts are gray pleather. Driver seat has a small tear, otherwise all seats are good. Floor is some sort of plastic sheeting (kind of reminds me of kydex) - very resistant to scratching - laid over plywood. Has front and rear AC, both work well. Issue with it is that the flapper in the rear that selects between heat and AC is broken. The solenoid seems to work, but the actual flap is busted. I had replacement before I moved - I'm sure its in the garage somewhere... I'll keep looking for it. Factory headliner has been moved up to top of high-top roof. Due to the office configuration, there are some small flourscent lamps installed. One has bulbs and it works. Others don't have bulbs. Again, don't drive it enough to have worried about fixing it.
Body: Front R fender and passenger door had been replaced at some point - key doesn't operate lock and the paint wear is different at that wheel than at the rest. This door also pinches up against the fender when opened fully. Haven't looked into it further as we drive it less than 10k a year. Some paint wear behind the other 3 wheels due to larger tires kicking up rocks. Right rear corner has been kissed by rear bumper. Bumper doesn't appear original. Front bumper appears to be a Ranch Hand (styling cues are all there) and is showing some rust. Molded in body crease on driver side has some paint loss inside the crease. I'm blaming the water based paints as there is nothing else that looks like it would cause paint flaking in this area.
Some more pics below. Not much of the interior as I figured most of you would be gutting it anyway. Was my original plan, but then we bought a camper. Used this to pull a 26' travel trailer. Never overheated it, just took it nice and easy going through the mountains. Let the gears do the work. And with the camper, it does have a 10k hitch and a Tekonsha brake controller.