My AC always blew cold, then started getting a little warmer and warmer for many months then the light started blinking I tested the relay and it works. It started working again after not working for a couple months but didn't blow super cold, then blinking light again. When turning the AC on you can see the clutch move just a tad and then the light blinks again. I put the gauges on to try and add refrigerant and got the readings in the picture. Explained it to a mechanic and he said I need a new compressor and receiver dryer. Does this sound accurate to you guys? I am thinking about doing the work myself, I do have the vacuum pump to suck the system back down. Any advice would be appreciated!
scottmss9
AC problem
My AC always blew cold, then started getting a little warmer and warmer for many months then the light started blinking I tested the relay and it works. It started working again after not working for a couple months but didn't blow super cold, then blinking light again. When turning the AC on you can see the clutch move just a tad and then the light blinks again. I put the gauges on to try and add refrigerant and got the readings in the picture. Explained it to a mechanic and he said I need a new compressor and receiver dryer. Does this sound accurate to you guys? I am thinking about doing the work myself, I do have the vacuum pump to suck the system back down. Any advice would be appreciated!
Attachments
Key questions:
1. What were the high side and low side pressures BEFORE you added refrigerant?
2. What was the engine RPM when you took your gage photo?
3. Exactly how many ounces of refrigerant did you add?
4. Are the serpentine belt and the belt tensioner both in perfect condition?
1. What were the high side and low side pressures BEFORE you added refrigerant?
2. What was the engine RPM when you took your gage photo?
3. Exactly how many ounces of refrigerant did you add?
4. Are the serpentine belt and the belt tensioner both in perfect condition?
It did not take any refrigerant at all, so none got added
Rpm was at idle, tried revving the engine and the gauges didn't change.
The serpentine belt has about 20,000 on it, same as the pulley
Also after turning the AC button on and off a couple of times the compressor did run once for a about 45 seconds, that's when I took the pic of the gauges.
Rpm was at idle, tried revving the engine and the gauges didn't change.
The serpentine belt has about 20,000 on it, same as the pulley
Also after turning the AC button on and off a couple of times the compressor did run once for a about 45 seconds, that's when I took the pic of the gauges.
With the engine running at ~1,500 RPM, AC clutch engaged:
Low side pressure should be ~22 - 36 PSI
High side pressure should be ~196 - 228 PSI
Your high-side and low-side pressures are almost identical.
During those 45 seconds when the mag clutch was engaged, did the pressure shown on the gages ramp up quickly, and then stay essentially stable during the remainder of the 45 seconds?
The symptoms would point to a failed compressor, less likely a blocked expansion valve.
You can always disconnect the compressor from the wiring harness and jumper it directly to 12V to be able to get the compressor to run for a minute or two to get stable pressure measurements.
Be careful to apply 12V to the magnetic clutch windings, and not the compressor tach.
Low side pressure should be ~22 - 36 PSI
High side pressure should be ~196 - 228 PSI
Your high-side and low-side pressures are almost identical.
During those 45 seconds when the mag clutch was engaged, did the pressure shown on the gages ramp up quickly, and then stay essentially stable during the remainder of the 45 seconds?
The symptoms would point to a failed compressor, less likely a blocked expansion valve.
You can always disconnect the compressor from the wiring harness and jumper it directly to 12V to be able to get the compressor to run for a minute or two to get stable pressure measurements.
Be careful to apply 12V to the magnetic clutch windings, and not the compressor tach.
I will hook up the gauges and see if I can get the compressor running to get a more accurate reading. After I was getting that high reading the first time I shut it off and disconnected. I am fairly certain that my problem is the compressor, what else would I need to replace? Somebody mentioned a metal screen or filter of some sort on the FJ?
As your mechanic had said: a new compressor (as you've also pointed out based on the evidence found) and note that he also recommended a new receiver/dryer because once you open the system it is wise to install a new one of those (its job is to absorb moisture in the system, and a bunch more moisture was introduced when opening the system allowing ambient air in).
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