Coil Pack keeps going bad

[jeffreylane]

Yeah, I've been trying to think through how this would be effecting the coil / ICM. I guess it could be putting extra strain on the engine? but then again so does going up a hill. I'm guessing it lies somewhere with the electrical that engages the a/c clutch. If it keeps going on and off, or maybe freezes when it's on, maybe that overloads that electrical circuit and somehow affects the coil pack. It definitely has something to do with it. If all goes well, I"ll change it out on Saturday. Hopefully the bu will be rolling again soon. I would love to hear someone explanation of how this could cause the coil pack to go out if anyone has a hypothesis.

[jeffreylane]

Ok, I got the air conditioner compressor swapped out, but not gassed back up. Put a new coil pack on it, and it cranked fine. I drove it around town for about an hour today straight. Cutting it off and on at times to test it. Everything ran fine. I think I need a new set of plugs from the misfiring, but other than a slight miss, it ran fine. Cranked up great every time. Not celebrating victory yet though, it has been "fixed" before. I tried to add r134a to it (taking this time to gripe about the placement of the low line input. My wifes cavalier right on top. didn't even get dirty. then had to fish my arm and can down behind the hot motor on the bu......arghhhhhhhhhh, ok, got that out of my system). Anyways, the gas was leaking out pretty fast out of where I hooked the lines back up to the compressor. I didn't look at it close, but I'm guessing there are o-rings on this part where to 2 lines hook up at the compressor. I"m guessing, o-rings in which I need to purchase. Tried to look them up on autozones website, but no luck. Anyone know where I can get these o-rings?

[pocket-rocket]

Yes, there are o-rings there. I imagine if you take them in to the parts store they should have some. Worst case, you could go to the dealership to get them. I can't imagine them being too expensive, I mean the distributor plug o-ring is fairly cheap. If you go to the parts store, make sure you tell them the o-rings are for A/C. I'm not sure, but A/C ones could be made of a different material than normal o-rings. Maybe someone else with more experience in this area will chime in. Was it a new compressor, or a used one? If it was new, I'm shocked it didn't come with new o-rings.

[96lumina]

Let me explain the electrical load on the coil pack, good catch!...when the A/C clutch is engaged it draws current just like a blower fan motor does on your heater...now if you were to stop the blower fan while it is still trying to run, keeping it from spinning while still drawing current it will draw as much as it can until the alternator maxes out or until the circuit protection pops(fuse/circuit breaker)...with this much draw it is overloading the the other components and causing a direct short to ground after the compressor heats up enough...what you can do is figure out why your circuit is not protecting the other components...but if you want a simple solution just install a 30 amp water tight fuse in-line of your A/C compressor, if your new compressor decides to go south then the fuse will blow and your car will still run fine...I hope this info was helpful

[pocket-rocket]

Correct me if I'm wrong, but isn't the A/C clutch just a simple electro-magnet, which really isn't going to care (or draw more power) when the compressor stops spinning? Even if it were the case it sounds more like if that has something to do with it, the compressor clutch would be pulling the system voltage down, then when it cuts out the regulator wouldn't be coming out of a full load type of setting which would over-volt the ICM, but that still doesn't explain how it's eating coils too. Even if what I said were the case, I would think the ICM has some sort of regulators in it (like the ECM) to keep from damaging the circuit if the regulator were to short out or something freaky happened to the system voltage.

[96lumina]

Correct me if I'm wrong, but isn't the A/C clutch just a simple electro-magnet, which really isn't going to care (or draw more power) when the compressor stops spinning? Even if it were the case it sounds more like if that has something to do with it, the compressor clutch would be pulling the system voltage down, then when it cuts out the regulator wouldn't be coming out of a full load type of setting which would over-volt the ICM, but that still doesn't explain how it's eating coils too. Even if what I said were the case, I would think the ICM has some sort of regulators in it (like the ECM) to keep from damaging the circuit if the regulator were to short out or something freaky happened to the system voltage.

Yes!, the A/C is a electro-magnet, this is whey GM installed a diode at the compressor so it will not spike the electrical system as it engages and disengages...as for the electrical draw from the A/C, in a world were everything works great, sure...very little load, now take a very worn compressor that is on its last leg and engaging the compressor would be like installing a direct short to the system that shares the same components...I'm not familiar with this particular vehicles wiring system but it sounds like GM either did a booboo or some tweeker has been under the hood at one time...I know the A/C has a fuse and am curious as to why it is not blowing out and why it is sharing with the ICM and the coil pack?!...does the wiring look to be original or does it look like Micky Mouse has been working under your hood?...if it were me I'd start with an electrical schematic and determine how this stuff should be hooked up...sounds to me that somewhere somebody bypassed the original A/C fuse, maybe...but you should look into it cuz if you were to pull the A/C fuse the car should still run...this is why I say you should get a book to see how these components are powered cuz something to me doesn't sound right.

[jeffreylane]

ok, I've drove to work 2 days on it and so far so good. Yesterday, I even added about 10 extra miles to the trip home to make sure I gave it ample opportunity to mess up if it felt the need. The wiring should all be the original. The motor was swapped, but the factory a/c retained, so the wiring is all the same as well. The only wire that appears to have been changed under the hood is the crank sensor wire (which I changed).

[jeffreylane]

also, just to add. When the coil pack would go out, I did not ever check individual coils to see if they went bad or just the ICM. More than likely it was the ICM going bad since it would not start or seem to fire on any of the cylinders.

[96lumina]

At least it seems you have a check on the issue...I would install a fuse any way just to be safe.

[jeffreylane]

yeah, I believe that to be good advice. I'll install a fuse. I guess I should just install it on the hot wire just before the plug into the compressor?

[96lumina]

You got it!

[pocket-rocket]

Maybe ohm that diode on the A/C for some comfort as well. If it's shorted it's doing nothing in there.

[jeffreylane]

cool, I'll try and get that done this weekend. Right now I'm fighting the a/c in my wife's cavalier (j-body). It's always something. As for the bu, it's been running fine since the compressor change. I really appreciate the help guys.

[60dgrzbelow0]

cool, I'll try and get that done this weekend. Right now I'm fighting the a/c in my wife's cavalier (j-body). It's always something. As for the bu, it's been running fine since the compressor change. I really appreciate the help guys.

Jeff... Those "O" Rings are actually HVAC sealant material buried inside large crush resistant washers with one being slightly smaller for the liquid high side line and the other being larger to accommodate the return vacuum low side line. Take the ones off of your old compressor and show them to the desk man at Autozone for a common replacement of same. You did not mention "pulling down the system with a vacuum" or replacing your accumulator (drier/filter) but if your system was opened for any length of time...especially in hot, humid weather... there is a good chance that your Silica Gel pack inside the Accumulator became totally saturated with being exposed to water saturated air at one atmosphere... so it is a good idea to purchase an HVAC "O" Ring Kit, A Four Ounce Bottle of PAG Oil and a new Accumulator, too. After dipping the "O" Rings in some PAG Oil (Then... Cap that bottle tight, Bro') then tighten everything down and either borrow a small vacuum pump and a set of Automotive HVAC Gauges Manifold and look up how to do this on YouTube. Charging a system with R-134A refrigerant without a vacuum down of the system to remove both water, dirt and non-condensable gases will ensure that your system accepts a decent amount of R-134A and cools...without having any residual water in the lines to freeze up and block the system. If your a/c compressor is new...makes sure you put 2 Oz of PAG Oil in the unit and once installed ...hand turn the pump at least ten times by hand to move the oil along and not cause the compressor to lock up. Put the other 2 Oz. of PAG Oil into the Accumulator, too. The system is equipped with a low refrigerant pressure switch which will NOT turn the electromagnetic clutch on the compressor... so make sure you put at least enough R-134A into the Low Side (Blue) fitting first until the clutch activates and gradually stays on ...or else the compressor will not engage and you will not be able to top off and confirm the cooling status if the low side pressure is below 40 PSIG. Don't overcharge the system!!! You can buy a small vacuum pump from Harbor Freight that will serve you well and truly for all your auto a/c work.

[jeffreylane]

Ok, I made it about a month, now back to the same problem. I had been driving the car with the compressor unplugged, in case that was the problem. I finally got the seals for the compressor and gassed the ac system up. I drove the car for a week with the ac. That was nice, lol, it's real hot and humid here in Memphis. I was basking in the coolness of the a/c and remembered I haven't put a fuse in-line. Bad on my part. After a week of driving,it left me stranded again. Right at a busy intersection. After about 30 min of being in the way during rush hour waiting on the tow truck, the traffic thinned. I said what the heck, and got out and hooked a coil pack up to it that I had in my trunk. It fired right up. canceled the tow, and drove on to work. Driving back home, I made it about a block from my house and it died at a red light again. This time with the ac electrical un-hooked. After about a minute, it started back up, back fired, coughed and limped the block home. Then it would not crank back up. I replaced the coil pack back to the original,and it fired up again. While on my lunch today, I was playing with the wires, and unhooked the hot wired on the alternator to make sure it had a good connection. I had my battery unhooked during this. Of course during this, I was moving all the wiring around by the coil pack and alternator area. Got it all hooked back up, and it would not crank. This time it happened and the motor wasn't even warm. Swapped our the coil pack with the one in the trunk (this time just hooking it up and setting this coil pack on top of the one mounted because I had limited tools). If cranked up, and I drove it home after work without problems. I am at a lost, stressed, and getting very very tired of riding in tow trucks.