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Hey all! My issue involves AC that only blows hot air. The weather is heating up and there will be more questions about this.
Isn't it helpful to keep everyone from guessing when I disclose in the post title the year C4 we are talking about?
I hope everyone is hunkered down and staying healthy with this Chinese virus running rampant.
Here's the story. AC acted normal last year with cold air at the vents consistently.
No cold air this spring, only hot air. I noticed that the AC clutch was not engaging. I did the diagnostic on the HVAC system and it shows 09 low freon. I added freon to the limit without overfilling. As I was adding, the AC compressor began cycling as normal, but has since quit. However, no cold air was coming from the vents. I jumped the low pressure sensor and caused the AC clutch to engage, but it is intermittent and won't always engage. I have checked the fuses in the panel on pass side, all good. I'm running out of ideas, possibly the low pressure sensor needs replacement. Suggestions and comments please.
There is refrigerant with florescent dye available. Black light should reveal leak if nothing obvious remove blower module look for dye in evaporator case.
Unless someone converted it to R-134A it has R-12 which is very expensive. Without a set of gauges, there is no way to tell what the problem is. What kind did you put in it? If you bought one of those 12 oz cans at the parts store you probably bought R-134A and if you added it to R-12 you will have to have the shop drain and flush the entire system. If they have to do that you should go ahead and convert it to R-134a. No matter what you did without a set of gauges you can't fix it properly.
Car was converted to R-134A several years ago. I'm sure that I have a small leak in the system. Ice cold before weather cooled down last fall and car was parked over the winter months.
Some leaks are so small you can recharge the system and it will work all summer, if your lucky this is what you have. But, you still need a gauge to fill it, having too much is just as bad as not having enough and without a gauge, you are just guessing. If you have a harbor freight store close by you can get a set of gauges a lot cheaper than taking it to a garage.
I had a similar problem on my 92, compressor would not kick on. Had gauges and found levels OK. Cause was the compressor cycle switch. Changed it and now all OK
I'm thinking that will be the way to proceed. My gauge shows level of coolant to be spot on. I'm going to change out my compressor cycle switch and low pressure switch since they are original to the car.
Although against my better judgement, I will probably end up taking it to a shop to have the AC system checked so they can throw parts at it.
Throw what parts? If you have a leak, you need to fix it. Soon as you open it up, I would change the receiver/dryer. If it has never been done and it is R12, I would, and did change the rubber lines to supposedly R134A rated hoses.
Some leaks are so small you can recharge the system and it will work all summer, if your lucky this is what you have. But, you still need a gauge to fill it, having too much is just as bad as not having enough and without a gauge, you are just guessing. If you have a harbor freight store close by you can get a set of gauges a lot cheaper than taking it to a garage.
Unless you can put up with having no AC, I would just change it so as not to have to worry about what happens when it gives and keep spending money topping it up. Just fix it once and get it over with. OTOH, if you are selling the car, top it up.