AZJeff

If roll pins bother you, consider “spirol” pins. https://shop.spirol.com/viewitems/coiled-spring-pins/inch-sizes-heavy-duty

I used these in conjunction with relays: https://www.amazon.ca/dp/B07MRB4R3D/ref=sspa_dk_detail_1?psc=1&pd_rd_i=B07MRB4R3D&pd_rd_w=3GNmU&pf_rd_p=60f4d8bb-ce34-4daf-9823-4864ac29e442&pd_rd_wg=XTY8q&pf_rd_r=TS7E10ANJCH1NDBMPKBD&pd_rd_r=ed70d297-09cf-4a43-8bbe-fcbbe6fb3d28&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUFJODI5RFVSU1RRQVMmZW5jcnlwdGVkSWQ9QTA0NDk1OTgyT1BXUlUzWjJRS1YxJmVuY3J5cHRlZEFkSWQ9QTAyNTE0OTYzR0Y0SlNWWlc4MUU1JndpZGdldE5hbWU9c3BfZGV0YWlsJmFjdGlvbj1jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ==

VERY good point. And the KJ discs are plug and play, once you adapt some appropriate parking brake cables.

Yup. A KJ 8.25 is just as usable as one from an XJ once the spring perches are changed to accommodate MJ springs.

Yes, it's a Dana 30 on all MJ's with 4WD. And yes, the "carrier" must be removed to remove/install the seals, and sometimes is referred to as "the pumpkin".

Have you confirmed the oil pressure by using a mechanical guage? This is the first step, because oil pressure senders are known to go bad relatively often.

Oil pumps are pretty cheap. They run $25-75, depending on brand, on Rock Auto. If there is any doubt, spring for a new pump.

Most PS pumps are incredibly simple devices inside. They have a series of vanes attached to a central hub that are spring loaded to rub against the outside of a cylindrical cavity. The vanes are often made out of some sort of plastic-y material, so they don't wear the inside of the cavity. The vanes will drag when dry, but when the pump is filled with some sort of oil (PS fluid or ATF), the drag will drop down, but will never be totally zero. (You cannot spin the shaft and expect it to continue to spin more than a quarter of a turn after letting go.) Put some PS fluild in the pump, and see if it's any easier to turn.

Nice color!👍

Rotate the shaft by hand. It should turn smoothly and easily.

You might want to secure the new, much larger capacitor. In the electronics assembly biz, we used "elephant snot", a kind of adhesive that is semi-pliable. A hot melt glue gun would do nicely.

Actually, when I am working on something where I know I won't be dropping big parts (like instrument panel stuff, or lighting) I often wear sandals in the garage. Of course, when it's 110* out, sandals are more comfortable than regular shoes. To the OP--the drag you are seeing on the wheels seems normal for a disk brake setup. The pads always drag slightly on disk brakes, and what I see/hear does not seem abnormal. If there were issues with the hub bearings, those are best detected by removing the wheel and caliper, and turning the hub by hand. Even better, when possible, is to remove the axle shaft, so as to eliminate any friction/noise from any source except the hub. A good hub will turn smoothly, with no noise. It won't "spin" if you give it a good turn, so don't' freak out if it stops quickly after you turn it.

Concerning that rasty looking master cylinder reservoir: I would place bets that the stuff you see in the reservoir is probably scattered throughout the brake system, and none of that will help make the brakes function as designed. As "Minuit" mentioned, that is some of the nastiest looking brake fluid I have ever seen, and is a good indication of the condition of the rest of the hydraulic system. I would take the MC off the vehicle and disassemble and clean it. If the seals and bore look OK, then reassemble and reuse. If you see damage inside the bore, then get a new MC. While the MC is off, now is the time to flush all of the lines with compressed air, to push out the old fluid and the crud that is probably floating in it. I would also give serious consideration to replacing the front calipers and wheel cylinders. I would also consider removing the rear load sensing bias valve and clean that thing as well. Putting new pads/rotors on a brake system that had that much crud in the MC is sort of like painting over the rust holes in the body.

That is VERY impressive. Those rails are better than many of the commercial aftermarket creations I have seen. NICE WORK.

When they are dangling, I just tie wrap them to the parent wiring harness to keep them out of the way as best as I can.

If the production volumes for a particular suite of options was low enough, the cost of making a special wiring harness might be more than just throwing in the wires and connectors into all vehicles. AMC was, in general, making a whole lot less cars than the "big three" back when they were around, so this is probably their logic (and is probably backed up by some bean-counter's analysis.)

Let’s go back to specifications—what is the STEADY STATE draw of this fan you have chosen? Then add 20% for start up surge current to figure out peak current. Now how long are the wires from the 12v source to the fan motor? Now figure out the voltage drop for a given wire gauge and wire length using the below simple calculator: https://www.rapidtables.com/calc/wire/voltage-drop-calculator.html you want your voltage drop to be 0.25vdc or less, so adjust your wire gauge accordingly.

The clutch is just a electromagnet whose coil creates the magnetic field when 12V is applied. The fact that applying more voltage makes the clutch work is damnning evidence that the clutch coil is toast. You may or may not be able to obtain just a new clutch assembly, depending on which brand of compressor your MJ has. I am not reallly up to speed on which compressors they used back in the 1980's, so you might have to do some searching on line for a parts source.

Yup. Thirty year old grease, mixed with dust and other crud, makes the door latch and lock mechanism prone to sticking, as well as being hard to actuate to begin with.

THIS is most like the issue. Eagle speaks from experience, I am certain.

VERY good point. If you put in a large fuse, yet use (relatively) small guage wires, you wind up using the wires as the fuse element.

Acrylic is used for guage cluster lenses because it can be quite optically clear and yet easy to mold. Unfortunately, it is also brittle, and fractures in impact relatively easily. This is why it is a poor choice for headlight lenses.

The plastic for the gauges is acrylic, whereas headlights are polycarbonate. you can buy special plastic polish from Amazon intended for use on acrylics. I used that very successfully on my tail lights as well as gauge lenses.

The fan specification should tell you the current draw or the power draw (in watts). Take the wattage and divide by twelve (battery voltage) to determine current draw. Caution—startup surge current can be much higher than steady state current. Take the steady state current and add 25-30% to that when selecting a fuse. actually, I prefer self-resetting circuit breakers over fuses for cooling fans. Nothing sucks more than to be stuck by the side of the road because your fan won’t run because of a 25 cent fuse That failed due to fatigue.

Those flanges are a press fit onto the water pump shaft, and are designed to be an interference fit during manufacture. It sounds like the one you got is defective. I would expect something like that from Autozone or the like, but not from Mopar. Then again, no brand is TRULY without a defect now and then. You got lucky and won the defective part lottery from Mopar, I guess.