AC Compressor Not Working

The odds greatly favor that you are most likely low on refrigerant which would cause the low pressure switch to open, preventing the compressor from operating. The typical static pressure (engine off) needed in the system to close the switch is 30-40 PSI.

Other issues could cause the problem - electrical connection broken, etc but the low pressure is the "usual suspect" in this situation.

 

If its the same as the mondial, you should find the low pressure cut out switch on top of the drier in the front boot. This has 2 wires so if you either short them or open them ( cannot remember which) , the compressor clutch should operate if it is low gas pressure

 

Short (jump) them.

 

Hopefully I'm not hijacking this thread, and merely "furthering the AC discussion": on the subject of AC compressors: I've got my whole engine apart and being rebuilt, so the compressor is out. I can't find a rebuild shop in town; do people have these rebuilt anywhere? Am I over thinking it, and should just chuck the thing back in? Also, is there a more affordable source for the rubber hoses for the AC system? The OEM parts are insane, it looks like one could easily spend over 1k on hoses...

 

You can buy bulk AC hose and fittings. Bring your old hoses and the new parts to a shop that sells and services hydraulic hoses. They have the equipment to crimp the ends on the hose.

If you make your own hoses, try to get the reduced diameter hose because it is easier to pull through the body cavity. I pulled my new hoses through with the new fittings attached.

Here is a link to get you started.

https://coldhose.com

 

These cars used to run on freon 12 and now 134 a is used. The old hoses for f12 are no good for the modern gases as the hose will leak gas . Be sure to get the updated hoses in case u r using 134a as f12 now near unobtainable ( does dreadful damage to environment )

 

Brilliant-thanks folks! Looks like I could save a ton of money rolling my own. A few more follow up q's:

-will the compressor support R134 with updated hoses, and no further modifications?

-should I bother rebuilding the compressor, or is this a "low liability" part? thanks!

 

The original hoses are very long and permeable to r134. Need to top with one can of r134 every year or two. Modern ac barrier hose is the long term solution. The system will put out less cooling than with the r12, but will function adequately with r134.

 

"The system will put out less cooling than with the r12, but will function adequately with r134."

Well...not sure I'd agree with that.

Of course, much of that depends on the climate where the car is located and your personal preference for cabin temp. For me in South/Central Texas, it functions poorly with R12 and abysmally with 134!

Re hoses - R134 has smaller molecules than R12 so original-type hoses that are NOT permeable to R12 ARE permeable to R134.

FWIW, there are propane-based refrigerants that are actually more efficient than R12 and have larger molecules than either R12 or R134. They work well and, in my experience can elevate an OEM 328 (and I assume, a 308) A/C system capability to "almost fair."

HOWEVER, they are not certified in the USA for use in auto AC systems so using them is a DIY thing. There is a general view that they will eventually be tested/certified because they are more efficient and have no ozone-depleting characteristics. But so far, current producers of automotive refrigerant gases have successfully lobbied against their use. Consequently, propane-based refrigerants have not been tested for automotive use by the appropriate US agencies. They are OK/used in other AC/refrigerating applications.

 

I have a Sanden compressor, new hoses, my AC works great with the R134 . It actually gets cold enough to where i can actually lower the knob once the inside cools off.

Thank you

 

Before sundown?

 

Yes for sure, at first, the place that built the hoses did a lousy job on the fittings, I had to have two of them changed out already, the guy I just had fix it, used better quality fittings on the compressor side. The shop that installed them gave me my some of my money back on the hose installation and parts, the mechanic that they had working on my car went back to Italy, so they opted out of the repair, but thats ok, they did a great job on my suspension rebuild, among a bunch of other stuff, belts, tensioners , new water pump, and some more stuff.

Thank you ,

 

Do you mind sharing which model Sanden? And did you upgrade just the compressor, or did you do a full kit, a-la Classic Auto Air? Thanks.

 

My car is at my shop, I can go look to see if there is a model #, I had the York unit, but for 19 years I never wanted AC, so once I decided to get the AC fixed, I could not locate a" new " York compressor that came with a clutch.( the York clutch was the problem ) I called Charles at Italian Car Parts. and he said he had a compressor with a clutch, I did not know it was a Sandan until I read up on it here at F CHAT. So Im not sure a sandan is an upgrade, but like the other fellow said , the R134 is a downgrade from the R12, Charles said this unit was better than a York, I dont know if thats true, because I never had my York unit working in my car from the day I bought it.Yes, I had to have all the hoses changed, heater / dryer, and whatever else. I have to accept that even though my AC works pretty good, its not like my 2 trucks.

 

This is the compressor Retroair uses in their308 AC upgrade kit. I modified the support plate for an easier removal/re installation. Hope this helps
Image Unavailable, Please Login Image Unavailable, Please Login