Is there any relationship between the a/c system and the CEL?

Nope...Pull the code with a good scan tool and see exactly what it is...

I didn't think there was but wanted to double check. Must be a coincidence. Getting it scanned Wed.

Bought me a cheap Autel (spelling?) off Amazon a couple of years ago so I could pull my own. I think it was around $30 and it's been well worth it. They're probably cheaper now.

Mine was $269.00 and it was well worth it. I got tired of going to O'Riley's to borrow theirs.... EZEARL, your '96 should be an OBDII equipped vehicle. '96 was the first year (I believe) chevy started using this, as it was first used with their new Vortec engines. Here's a little more about the OBDII system:

Unlike earlier OBD systems that set a DTC when a sensor circuit shorts, opens or reads out of range, OBD II is primarily emissions-driven and will set codes anytime a vehicle’s emissions exceed the federal limit by 1.5 times. It also will set codes if there is a gross sensor failure, but some types of sensor problems won’t always trigger a code. Consequently, the Check Engine light on an OBD II-equipped vehicle may come on when there is no apparent driveability problem, or it may not come on even though a vehicle is experiencing a noticeable driveability problem.

The determining factor as to whether or not the Check Engine light comes on is usually the problem’s effect on emissions. In many instances, emissions can be held in check, despite a faulty sensor, by adjusting fuel trim. So as long as emissions can be kept below the limit, the OBD II system may have no reason to turn on the light.

CHECK ENGINE LIGHT

The "Malfunction Indicator Lamp" (MIL), which may be labeled "Check Engine" or "Service Engine Soon" or a symbol of an engine with the word "Check" in the middle, is supposed to alert the driver when a problem occurs.

Depending on how the system is configured and the nature of the problem, the lamp may come on and go off, remain on continuously or flash - all of which can be very confusing to the motorist because he has no way of knowing what the light means. Is it a serious problem or not? If the engine seems to be running okay, the motorist may simply ignore the light. With OBD II, the Check Engine light will come on only for emissions-related failures. A separate warning light must be used for other non-emissions problems such as low oil pressure, charging system problems, etc.

THANKS for the info. I lucked out with my '96 XJ. It's OBD I so I can access it by key. We've been having trouble with a/c compressors staying alive. Everything has been replaced. Yesterday the CEL came on(first time since I replaced all O2 sensors and IAC)and a few hrs later the compressor started squealing then locked up. Got to be contamination from somewhere.

You talking about a 96 blazer (as the title says) or Jeep (XJ)???????

Blazer. A/C system has been completely replaced but it continues to eat compressors within a couple days and sometimes less. This last time the CEL came on a few hours before the compressor went out. Thought there might be a connection.

How does the compressor go out? Bearings? Leaking? It's an independent system that just bolts to the engine and is run by a belt. It could run without the engine if there was another way to turn the pulley.

Bearings. Bad one on it now will shut the motor off while idling when engaged.

The pulleys might not be properly aligned or maybe the belt's too tight. Maybe dirt in the system or just a case of a crappy compressor rebuild.

We're thinking contamination. Everything else you mention checks out good. We've tried two different brands. It goes back Monday for the 6th compressor. His equipment is good and he's done other a/c work while doing mine with no problems. Even had a priest do an exorcism last time. LOL

If the belts & pulleys are good, contamination is about the only thing left to go bad.

Actually had thought about eliminating the a/c but I've put too much $ in to it and the bypass pulley systems aren't of the best quality.

Need to replace the dryer and the orifice tube. It's like a screen filter. If you are not doing this when you are changing the compressor, you are asking for trouble. Also, putting in the wrong oil or not enough oil will kill a compressor.


Clyde

Not sure if that's being done or not. Problem started with the first replacement compressor. Original just leaked no bearing noise at all. This guy services all the vehicles for the local schools,DNR,and both local and state police. He's stumped. Goes back Monday.

I do APPRECIATE the input.

Are you using a flush to clean the system.

Should or should not use? Either way I can ask him about it along with the dryer and orfice tube issue. THANKS

Sounds like it's possessed by the devil... I'd find a different priest to do the exorcism right this time....

About to give it a proper burial.

I used to have an older full sized Blazer. Running without the a/c in the summer was a hotbox. Only the front windows opened and the ventilation was lousy. I have the same problem now with a Bronco II that I inherited from my brother. The a/c doesn't work. This thing gets REALLY hot, too hot to carry my dog in back on summer days.

Just kinda frustrated with it. Been a pain since I've had it. Really need the a/c cause it's our primary ride and my 92 yr old mom lives with us. He'll get it figured out.

I hope you get it fixed. Good luck with it....I've had my fair share of working on Chevy's......

Thanks. I can use it.