3.8 ssei 1995 (ODB1.5)
- Took it to a shop to get a new compressor (old one was leaking - but a/c system worked OK while it had a charge).
- Shop ran it for a half hour after - no problems - went to pick it up, SES light went on and AC went OFF.
- Shop couldn't get a reading off the PCM - but not sure if they were reading it right (ie: ODB1.5).
- Car runs OK, everything seems to work, except CRUISE won't now. Checked all the fuses, limit switch connections - any ideas?????

You should go back to the shop and find out exactly what they did. They should be able to pull the codes and read the PCM.
Sounds like an electrical connection issue.

I know that you said you checked all the fuses and limit switch connections. Did you ensure that the compressor switch connection is tight and that no wires are damaged there?

And while I don't know what type of shop you took it to, but first of all, they own responsibility for this, IMO, and second they should have a decent scanner to read that OBD1.5 PCM. If they don't know what we're talking about, then we can give you all the info you need to set them straight.

And just for kicks, check your PCM connectors and ensure they are tight.

Thanks for the feedback,

The a/c guy wasn't a GM expert - so he actually farmed out the scanning to a GM delership - who'm I'm assuming would knowthe difference w/ odb 1.5. (I don't have a reader myself)
The dealership came back with a pcm fault. Nice. I don't trust that.
I have an appointment with a shop on Monday I used to deal with (I moved since then). These guys are pretty sharp should be able to help.

I had the car into the shop today (the ones who sold me the compressor). They checked the clutch/resistence for a short, pulled up the wiring and confirmes that the computer was protected by a fuse and a relay.

I just never heard of a computer dying with a new compresser install. I think I did hear of cruise control not working and that being related to the a/c...

BTW - I checked all the fuses/connections - all OK.

I think you're right in not trusting that. It'* still very possible that the tech made an assumption that since it had an OBD2 connector, that it was OBD2.

We've seen many a '95 owner post here about seeing the PCM fault, when the wrong scanner was used.

We do also know that the '95 PCM was a bit prone to failure, so unfortunately we can't rule that out completely yet, but I wouldn't panic at this point.

If they didn't unhook the battery terminal when doing the repair they could have caused an electrical problem with the pcm.

I finally had some time this weekend to take a look for myself. I did some surfing prior (on this site - on PCM failures) and noticed that there was a 3rd fuse bank to look at on the passenger side.

1- Engine compartment (firewall/passenger side)
2 - Under console - driver side
3 - under console - passenger side

So, after checking every connection and fuse found that the cruise not working was the clue I needed. A 15amp fuse marked a cruise/elec misc was the one! It was blown. Replaced it and system started working!

So... I also noted that the small plastic retainer was broken off the high limit switch in the rear of the compressor, and the plug was a bit loose.

Not sure if anyone knows if this circuit usually open or closed?

If this plug works loose, will it trip the fuse? I guess I could pull it and see what happens, but I just used plastic ties to tighten it up already - it ain't moving...

So, for anyone who has a clutch not engaging problem - note this extra circuit. I believe this is tied to the limit switch curcuits and will shut down the clutch circuit if not live.

One other thing...

We're talking 3 garages here, the orignal A/C guy, the GM dealership (who should have found it), and the garage/store where I bought the compressor.
Seems no one was smart enough to check for the damn fuse. The old saying if you want it done right, you gotta do it yourself seems more the rule nowadays than ever!

Nice job on the fix and also finding that other loose connector! (I don't know the answer to your question about that, but maybe Boosty will take a shot at it in the morning) These are always valuable things for the rest of us to know, especially us non-gearheads.

Oddly, I've noticed that if there was one thing that came back from the shop screwed up on my cars, it was invariably the cruise control. Before I started fixing my own cars again, I got pretty good at finding out where the shop had disconnected the cruise and not put it back together again . (It seems like about half the time a car comes back from the shop, even from the dealers, they forget to put something back together or even blow something out. In fairness though, a good shop recognizes this and will usually bend over backwards to correct it right away).

Frequently the AC connectors are broken by mechanics that don't take the time to figure out how to disconnect it properly. (it'* usually a tight area)

Not sure on the open or closed. I'd think it closed to engage..but who knows.