Hello All,
I've searched numerous sites but can't find a thread anywhere that touches on this particular issue. I've got a manual transmission 06' MCS with about 120k miles with a serpentine belt that seizes whenever the AC is turned on, otherwise everything works normally and I have no warning lights or issues with engine performance. AC will kick on normally then about 3-4 seconds later blows warm air and about that time i get the battery sourcing current light in the dash. The alternator is working fine prior to the AC being turned on (volt meter tested) and there are no unusual noises from the belt area prior to the AC being switched on. I replaced the serpentine belt to see if that was the issue (the old one was very worn, especially at the edges, but it has at least 50k miles on it and may be original belt so hard to tell if the wear is due to an issue with anything the belt drives or not). The new serpentine belt also seizes as soon as the AC is turned on and I'm not hearing any unusual noises or smelling anything burning prior to it seizing. Based on other threads which discuss serpentine belt issues, I'm wondering if the harmonic balancer is on its way out or if the bearings in the AC compressor or alternator are seizing and causing the entire system to stop turning? I don't believe its the alternator because it seems to be working fine prior to the AC being turned on, and I've never heard of bad alternator or compressor bearings seizing the serpentine belt in its tracks, however I didn't notice any obvious issues/damage with the harmonic balancer either. Any thoughts/suggestions are very much appreciated!

 

Is belt moving at all ? Does the pulley for AC compressor rotate after A/C turned on ? With a good flashlight you should be able to see it from up top.

 

Mine does something similar....albeit I haven't had the battery light go on (mainly because I turned the A/C off immediately as I noticed the problem), but in my particular case, my A/C randomly stopped working one minute, then started whining and significantly dragging the motor down the next. I was going 70mph on the freeway, and even at near full throttle after dropping a gear, it was quickly slowing the car down to ~45mph very quickly.

My understanding is that the compressor is the only A/C component that is able to physically resist the serpentine rotation, so that's probably a good place to start..but there's no telling that only the compressor is shot in your case since you don't have any other symptoms. In my particular case, the compressor was screeching and refrigerant film was deposited on the inside of my windscreen, so I knew that at least my condenser was bad as well.

If the serpentine belt is moving but the A/C pulley is not, and your A/C still has refrigerant, you might be in (relative) luck. There's a bunch of A/C compressor clutch/pulley kits for less than $100 on Ebay. . Good luck!

 

Bet the A/C clutch is frozen in place. Take a peek under the hood on the passenger side straight down in the front.

 

Your A/C compressor is almost certainly seizing up.
If you turn the A/C on, the serpentine belt will burn through quite quickly & you'll lose the alternator & water pump = no charging & no cooling = don't try to drive it far! Electric power steering will work as long as the battery lasts.
If you leave the A/C off, the clutch will continue to spin freely & the car is OK to drive, just no A/C.
I've had this happen on an old Ford.

 

Need to watch the crank pulley while it is running then have someone turn on the A/C. Watch to see if the belt stops but the center of the crank pulley keeps turning. If it does then the issue is the crank pulley "harmonic balancer". If the outer ring with the grooves keeps turning and just the belt locks up it is likely the A/C compressor.
If you need the crank pulley, go with the ATI damper
https://www.waymotorworks.com/super-...ulley-r53.html

If you need the compressor we have it too
https://www.waymotorworks.com/a-c-co...r53-denso.html

 

I went through something similar at 135K. Bit of advice, you will most likely need to replace your ac compressor or at least fix the ac clutch. But your alternator bearings, the idler pulley, the tensioner pulley and maybe even the harmonic balancer are most likely going to need replacing within the next 10k miles. Do yourself a favor and see if you can replace them all in one shot. I had to do it all - one by one and one after another.... not fun.

 

Thank you all for your inputs and apologies for the delayed response - I've been out of town for the holidays so I really haven't had an opportunity to do much trouble shooting since my original post. Based on your suggestions though, I went back and took a look at pictures I took of the pulleys when I replaced the serpentine belt, and I believe I can see a hairline crack in the rubber of the crank shaft pulley. I'll have a chance to investigate further this weekend but I'm leaning towards a failing CSP as the culprit. I'm thinking the load of the AC clutch engagement is too much for the rubber on the pulley to hack, but I'll check the AC clutch engagement before I dive into that DIY. If it does turn out to be the CSP, I'm planning on replacing it with the ATI Super Damper from WMW. From the reviews I've found, it's a solid product and reasonably priced as far as harmonic balancers go. More to follow and thanks once again to everyone for their thoughts.

 

I finally got around to pulling the CSP and it broke in two in my hands as soon as it came off the crankshaft. After a failed attempt at removal using an autozone generic puller kit that didnt fit, I bought the puller tool from WMW and it couldn't have been easier. I had the old harmonic damper off and the replacement ATI part on (also picked that up from WMW) in less than an hour. A couple of lessons learned from this install. The first is that when you reconnect the the nut holding the top portion of the ground wire to the motor mount (this is removed to enable increased access to the top of the serpentine belt area), be aware that it doesn't take much torque to break the housing shelf from the motor mount. Second, when you're putting the ATI harmonic damper on the crankshaft, be aware that the bolt provided in the ATI kit will NOT push the harmonic damper all the way onto the crankshaft - you have to use the original crankshaft bolt to seat the damper the rest of the way (about the last finger width or so). This is mentioned in the WMW directions but probably worth noting again here. Thanks to WMW for getting my very well packaged order to me quickly (2 days) with no missing parts. Also, thanks again to everyone for your inputs.
Stock Harmonic Balancer

WMW ATI Harmonic Balancer

 

Great Pic, Glad you got it together and back on the road.