Markm10431

hi guys. my aC crapped out, assuming it was freon, I added some. the air started to work, but only on the passenger side. I ran diags and I got a probelm with an AC circuit. a tech says the head unit is out but looking on line it sounds like the driver side actuator could be the issue.

any way of figuring out which one without throwing parts at it? and anyone have a ballpark on how much the actuators are? the had unit seems to be around $300

K-Spaz

They're about $90 if you've got the dual zone system. Any auto parts store has em. I've seen them on sale too. They're a horrible ripoff, it's the same parts as it is for the non-climate controlled system, but sans a pot in there, and those are 1/2 the price. However, they won't work without some serious mods to it. (I have done it though).

If they're not calibrating, they should throw a code.

They're not real fun to swap out, just fyi. Not impossible, but certainly not in an easy spot.

73Corvette

BigGun

The tech just wishes it is the head unit which is easy to replace. The actuator which is the most likely problem is a pita. Use the dic to pull the specific C5 codes and see if the actuator is crapping out. If no codes then low r134 will cause this exact problem.

Trios

I wish they didn't sell R134 in recharge cans. A car never gets 'low on freon' without a problem that needs solving, and charging an 'empty' system (really a system full of air and probably moisture) is just a disaster.

Markm10431

no codes. I had not run digs in a long time and there was a battery swap in there so I had a ton of codes. cleared them and the only ones that come back are an o2 sensor code and some U codes in RFA. never sae a HVAC code at all, the code i did see that was the AC circuit was in the first set (PCM?)

anyway, Iwhen i saw all the codes i figured most were from the battery swap and i was right they all went away and have not reappeared

Markm10431

yeah I know, but it was a quick troubleshoot. once I get the mechanical fixed then i'll have them evac and change the filter.. the whole bit.

the lil darlin is 14. she's due some aches and pains

K-Spaz

Mark, I had a similar issue years back. Here's a thread I made on the subject that has some pics and text that might help you. The part you want starts down about 10 posts or so.
https://www.corvetteforum.com/forums...-hates-me.html

BigGun

Until you get it repaired I would bet another can of 134 will get it operating as it should. At least for a while.

BigGun

True, but many older car develop very small slow leaks and can benefit from a quick recharge from a can. It only postpones the inevitable but it is a lot cheaper than an expensive repair. Agree you should never recharge an empty system this way. Only for topping off a system that has slowly leaked down.

ZZ06

Kinda know what you mean. I finally got my motor installed from a 11 month hiatus. Well wouldn't you know it, on the ride home (80+* outside) I wanted to run some AC. Nothing but hot air. Compressor was changed 5 years ago with a reman. verified it was working so took it to a locale shop and recharged the system as they said it was very low. Performance shop said they never disconnected any lines, just ziptied the compressor to the frame. My car is an 01 and it has never been charged while in my possession and ive had it since 45k and she just crossed 120k. 14 year old car....im not complaining having to recharge the system only once. So far its been working great with ICE cold air! this was 2 weeks ago

Trios

'Very low' isn't as bad as 'empty,' because 'empty' usually means that the system is full of air and moisture. Then you add freon to that to get the pressure up, the compressor kicks on, and the air in the system sends the pressures way out of spec. Add the moisture causing the lines and compressor to corrode, and you've got yourself a brand new A/C system coming up real quick (that's lotsa $$$).

You took your car to a shop, where they were able to tell you had some pressure in the system and top you up. Now, in your case you might not need another topoff again because the leak could have been caused by stress on the lines with how they manouvered the compressor. Hard to say. If it goes out again, though, you'll need to find and fix the leak or you're just throwing R134a into the atmosphere.

I can't stand the $45 'recharge' cans with attached hose that they sell at auto parts stores. You can't just connect a can to a dead system and expect everything to be great, but that's exactly what it says on the bottle. I think they're probably being pushed by the A/C compressor companies to keep them in business....

92GA

The actuators are NOT the same for a manual system and the duel zone systems. And rock auto has the wrong part number for the duel zone actuators, the ones they sell won't work on a C5 with duel zone. Just had a couple threads on this in the last couple weeks.

https://www.corvetteforum.com/forums...sues-help.html

Markm10431

well the guy that i was talking to said it's a grand to replace both actuators. is that crazy stupid or on target?

can a shade tree mechanic really replace them?

K-Spaz

Maybe you missed where I said "Sans the POT..." Look man, I took the parts from a manual one and repaired my dual zone one, though it wasn't a slam dunk. They are not very dissimilar. Total cost difference between them? $0.10

He's out of his mind. An hour under the dash and you can do them both for $200. It's a couple screws each (3 I think) and one electrical connector. They're just in a real tough spot to get to is all. I did mine without removing the dash, but I think the svc manual calls for that.

Vette10R

Question... I have a 1999 with the same issue, AC didnt work when I bought the car so I had a company look at it and they said I was low on refridgerent and had a leak somewhere. They filled it and it worked great, the next summer I only had AC on the passanger side not the drivers. I started thinking its the actuator gear that is broken but am also reading threads where it could be the leak/low freon causing this isue?

Im thinking I should try to re-charge it with a can from Walmart before attempting the actuator replacement. Are all C5s r134?

92GA

Yes they are. But remember if you over charge the system the head pressure will skyrocket on a hot day and may ruin the compressor.

BigGun

If you use the dic and pull the codes it will tell you if the actuator is bad. IF no codes then I would try a small can for a temporary fix. I doubt if you can seriously overcharge the system with these cans. Some come with a low pressure gauge if you are worried. Having a hvac shop do it would be the best option.

Markm10431

I got his estimate. actuators $277 and the head unit @ 600 ... Labor is reasonable @ $100

anyone have a part# for the dual zone control module? I know i can find one for less than 6, but I need a part number

Trios

Wait, why is he replacing the head unit at the same time? Put in new actuators and see if it solves the problem; how could he possibly diagnose a bad head unit with faulty actuators in place....