dudeinthepnw

Trying to get the AC on my 95 functioning properly again. It needs a compressor for certain I am not well versed in AC systems and it's one of the few things I would prefer taking it to a shop but I know how expensive this stuff can get to have someone else do it. So anyways, yesterday i jumped the low pressure switch to see if the compressor would engage. It "tried to" but made grinding/bad bearing noises. Hence why I believe the compressor needs to be replaced.

The weird thing about what happened yesterday was after I plugged the low pressure switch back in, I don't have any action to the blower motor/air going to the vents. I didn't touch anything else, I checked fuses/relays and everything seemed okay. Not sure if I somehow shorted something out when jumping the low pressure switch. I also know if I replace the compressor I need to do the drier/expansion valve etc need to be replaced. I'm pretty mechanically inclined just never messed with AC stuff before. Obviously need to have the system evacuated and all that fun stuff.

Does anyone have any advice? I'd like to have a little bit of comfort out on the trails on warm days lol.

Rambler65

Unfortunately if the compressor is grinding internally it has likely distributed debris throughout the system as its insides were grinding away. I assume that a 1995 model would use R134 refrigerant which means it has a parallel-flow condenser, probably evaporator as well. So unfortunately it's a much bigger job than just replacing the compressor and recharging. The system needs to be flushed to clear out debris and those components will also need to be replaced along of course with the receiver-drier. Expansion valve or orifice tube (depending which you have) also will likely be affected and need to be replaced. Then if you're going to do all that, do you really want to be putting it all back together with 25-year-old hoses? So you're looking at pretty much replacing everything. It is doable but a big job. Evaporator is probably the worst part of the job.

I'm not saying all this to be discouraging, but the reality is that any debris left in the AC system can destroy the new compressor, then you're back to square one, not to mention poorer for the experience.

There are lots of instructional videos on youtube that deal with working on AC systems. It is not rocket science but does require some tools and knowledge not used in more typical wrenching.

PatHenry

I replaced pretty much everything on my 95 except for the evaporator - which requires pulling the dash apart - and it was surprisingly inexpensive for the parts
Compressor - 110
Condenser - 50
Expansion valve (the little block attached to the evaporator) - 10
Hoses - 40-50 total for new HP and LP lines and one or two of the other lines. I have exactly 1 of the original lines.. I think it's expansion valve to receiver/dryer
Receiver/Dryer 10

Then >50 for a HF manifold gauge set and roughly 60 for the HF vacuum pump. While these are specialized tools, even the HF specials seem to be of decent quality and are re-usable and I don't mind spending money on -tools-. There is a member who owns/runs a shop and has used the HF manifold gauges commercially over years. I want to say "97Grand40", but don't quote me on it.. lol. His advice was to make sure you keep the little plastic caps and put them back on the manifold and connectors when storing.
I will say the manifold gauges and pump worked just fine for me after a year of storage and I intend to use the vacuum pump in the near future to help my sister-in-law with her currently leaky A/C. I can't re-use the manifold gauges on her car since it's a Prius and the PAG oil used in our old Jeep systems will contaminate the electric based hybrid system, so if I get to the point of pulling vacuum, I'll be buying a second set of the HF gauges for use on her car and any other hybrid systems I run into in the future.

But like Rambler said - the worst part of what you're dealing with will be pulling the dash apart to get at the evaporator - the rest of the system is pretty simple wrenching with mostly 3/4 and 7/8 wrenches to get the fittings apart (I had to cut the old condenser out since these 2 fittings were seized beyond the point of repair - if it's ALL new parts -- you'll have the luxury of cutting lines rather than fighting with a stuck fitting).
If you do go through with the evaporator replacement, just make sure you take care when attaching the expansion valve block. Since I was NOT replacing my evaporator, I had a heck of a time getting the 2 hoses to thread in.. it shouldn't be an issue going from new part to new part, but in my case, I DIDN'T take care and the hoses bend pretty easily... the slightest bend and it becomes hell trying to thread in the fittings.

dudeinthepnw

Well, fingers crossed but I think I got lucky. I replaced the compressor, before doing so I took it to a shop, had them evacuate the system. Put the new compressor in at home today and went back to the shop where they put it under vacuum, found no leaks, charged it up and I now for the first time since owning this XJ (2 years) have AC again. I put it off so long assuming it was going to cost me a grand to replace everything etc and that I didn't think it was worth it. Feels so damn good to have cold air!

Rambler65

Great that it worked out! Your old compressor must have been in the very early stages of failure and not contaminated the AC system. Sometimes you get lucky but it's not something I would tell someone to do (especially at a distance) given the potential consequences if things go horribly wrong.