1984 C4 Air condition questions
Thread Starter
Cruising
Joined: Feb 2010
Posts: 11
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From: San Jose CA
1984 C4 Air condition questions
Can anyone tell me what this switch / sensor is (see attached pic) on the back of the compressor? When it was connected, my a/c compressor would cycle on / off every 5 seconds or so.
From searching the forums, I think that indicates my a/c system is undercharged?
I want to charge it, but it's still R12 (I think). At my local auto parts store, I see conversion kits to R134A that simply put adapters on the high and low pressure ports, and they include a can of R134A with a pressure gauge on it.
Is that all there is to converting an R12 system over to R134A? Which ports are the high and low pressure ports?
Thanks!!!
From searching the forums, I think that indicates my a/c system is undercharged?
I want to charge it, but it's still R12 (I think). At my local auto parts store, I see conversion kits to R134A that simply put adapters on the high and low pressure ports, and they include a can of R134A with a pressure gauge on it.
Is that all there is to converting an R12 system over to R134A? Which ports are the high and low pressure ports?
Thanks!!!
Instructor
Joined: Oct 2006
Posts: 156
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From: Giddings Tx
That would be the low pressure switch and thats the suctions side(low side). As far as converting you just cant change out the freon. 134a uses a different oil than the 12. if you just change the freon the compressor will lock up. Get you some freeze12 (r12 replacement) and charge it back up.
Race Director
Joined: Dec 2000
Posts: 17,551
Likes: 26
From: El Paso Texas
Yep, that's the switch that tells the system that it's OK to engage the clutch and spin the compressor. If your refrigerant level is low, the system will cycle on and off as the pressure rises and falls.
If you're low on regfrigerant, you can add R-12 (if you have any), or convert to R134A. I did the latter....changed compressor and clutch, orifice tube, accumulator, and vacuumed system. Then charged with R134A and PAG oil. Ensure that you get all old mineral oil out, as the two are not compatible.
I get 43 degrees at the dash in 105 degree ambient temps. Not too bad. 9 years on it still works fine.
If you're low on regfrigerant, you can add R-12 (if you have any), or convert to R134A. I did the latter....changed compressor and clutch, orifice tube, accumulator, and vacuumed system. Then charged with R134A and PAG oil. Ensure that you get all old mineral oil out, as the two are not compatible.
I get 43 degrees at the dash in 105 degree ambient temps. Not too bad. 9 years on it still works fine.
Le Mans Master
Joined: May 2006
Posts: 9,226
Likes: 9
From: Irvine Ca
OP, Mine has a "permaleak"....which means I "permapurge" my system....it's a "running refrigerant change" system
All that is fancy speak for "i gotta leaky compressor"
What happens when you are low on refrigerant (whatever gas you chose) (from here forward referred to as "freon") The compressor kicks in and it sucks whatever freon is in the low side tube into it for compressing purposes like is supposed to do. When it sucks the low side the pressure drops too low and the pressure switch kills the power......as it is supposed to do. Once the freon has raced around the close loop system and the low side pressures back up.....the low pressure switch energizes the compressor and the whole cycle starts again.....
What you get from all this?? Surging idle and the compressor kicking on and off.
Once you fill the system to the proper PSI (low side) it will stop doing this all together.
You may find that in a few months the system is low again or not....
All that is fancy speak for "i gotta leaky compressor"
What happens when you are low on refrigerant (whatever gas you chose) (from here forward referred to as "freon") The compressor kicks in and it sucks whatever freon is in the low side tube into it for compressing purposes like is supposed to do. When it sucks the low side the pressure drops too low and the pressure switch kills the power......as it is supposed to do. Once the freon has raced around the close loop system and the low side pressures back up.....the low pressure switch energizes the compressor and the whole cycle starts again.....
What you get from all this?? Surging idle and the compressor kicking on and off.
Once you fill the system to the proper PSI (low side) it will stop doing this all together.
You may find that in a few months the system is low again or not....
Thread Starter
Cruising
Joined: Feb 2010
Posts: 11
Likes: 0
From: San Jose CA
Thanks for the info guys... I went ahead and ordered a Freeze 12 recharge kit via amazon.com.
Where is the low port nipple that I use for charging? Is it the port in the lower right hand side of the picture, on the metal tube returning from the radiator? Or, do I connect to the ports on the canister looking device, with the black caps on the ports?
Sorry for the "noobie" questions... not that familiar with AC stuff. thanks!
Where is the low port nipple that I use for charging? Is it the port in the lower right hand side of the picture, on the metal tube returning from the radiator? Or, do I connect to the ports on the canister looking device, with the black caps on the ports?
Sorry for the "noobie" questions... not that familiar with AC stuff. thanks!
Race Director
Joined: Dec 2000
Posts: 17,551
Likes: 26
From: El Paso Texas
You will connect it to the LOW side fitting, which is on the accumulator (the big silver cannister looking thing in front of the compressor). The on your kit will only fit the low side connector. DO NOT ATTEMPT TO HOOK IT TO THE HIGH SIDE. Very dangerous....the can could explode.
