Recently bought a 93 flare side mark 3 and has a few problems and what I can do to fix them. The speedometer jumps around when at a cruising speed. And also the oil pressure gauge jump around when at idle but is fine when driving. And also it has the electronic rear window and it doesn't work. There's also a botton on the side of the seat that when you press it there's a cylinder like canister that releases air. I was also wondering is it hard to put in a new window motor in?

 

Seems like a guage gear issue. Never heard of a fix other than new speedo. Have you checked your oil level? Critically low oil will cause the oil pressure gauge to do that. I'm guessing that electronic rear window is not stock. That's lumbar support connected to a pump to fill the bag with air and the other way is to release it. I've never done a window motor but need to in my truck. I hear it takes about an hour, pull the panel off, drill out the rivets, disconnect everything and replace. Most will say re rivet it back in, I've never heard of anyone having problems bolting them back in with either lock washers or lock nuts.

 

Unless you know what you're doing with rivets, bolting a replacement will be your best bet. What I mean by that is if you press too hard with the pneumatic hammer, you can bend the replacement regulator to where it won't work properly. And pop rivets are junk IMO. They wear too fast. Just make sure you use short enough grade 8 bolts with either a locknut (metal or nylon is fine) or a lock washer and nut. It'll hold longer than you'll have the truck.

While you have the panel off, make sure you look in the bottom of the door for rust and debri that might be blocking the drain hole. I've sprayed rust inhibitor Krylon in the bottom to help stave off the rust a little longer.

 

I'm going to guess you have a 302 engine. Does the engine have to be warmed up before the oil pressure gauge starts jumping around? You might try replacing the oil pressure gauge sending unit on top of the oil filter housing.

 

It's a 5.0(302) so yeah. But not really, it jumps around really only at idle but it does take a while but at cruising speeds it's perfectly fine

 

That seems to be somewhat common with 302 engines. The engine may have fairly low oil pressure when the engine is running slow. It shouldn't be a problem unless the engine is allowed to idle a long while at zero oil pressure.

 

Your oil pressure sending unit (which is screwed into the block just in front of the driver's side motor mount) is just an electrical sending unit. Not an extremely accurate measuring device. You could try a new one - they're not real expensive.
Your bearings could be getting a little worn - they do wear over time. Or your pickup screen for the oil pump could be getting a little sludged up which would give you lower pressure when it's not revving a bit.
Fresh oil and filter can't hurt

 

A window motor (in the door) is not too hard to put in, drill some 1/2" holes and undo the bolts. The window regulator (gear and arm part) is more complicated involving grinding off rivets and such like manuellabour was saying.
Whatever's going on in your back window setup - you'll have to uncover the workings and see what's involved. I think the only factory sliders were on the bigfoot models.

 

"There's also a botton on the side of the seat that when you press it there's a cylinder like canister that releases air."

Air horn setup, its just busted or needs servicing. Did you get it from a hunter?

 

The oil pressure sensor may be bad, the jumpy speed could be a bad speed sensor, or just diff oil with alot of metal grindings from wear.