Hvac Codes

[CornTaters]

Thankyou SKperformance. The two codes are 21 and 23. Prior to reading you FAQ all i/ve done so far is to check the AC/MGN relay (what's MGN?) and found that the NO contacts 5 and 3 were closed so i bought another one. the guy suggested i test the female contacts:there is continuity to ground on points 1,3,5 but not on 2. Is this the way it's supposed to be? we are the original owners of this 93 ES300 w/~90K city miles.

[George_Jetson]

code 21 is for the solar sensor, which monitors the ambient light in the passenger compartment. Code 23 is for abnormal freon pressure, (either too high, or too low). I would suggest checking the freon pressure, chances are that your pressure is too low. Has your car been converted to R134, or is it the original R12?

[CornTaters]

code 21 is for the solar sensor, which monitors the ambient light in the passenger compartment. Code 23 is for abnormal freon pressure, (either too high, or too low). I would suggest checking the freon pressure, chances are that your pressure is too low. Has your car been converted to R134, or is it the original R12?

Thankyou George. actually i'm researching the forum now on converting to 134. i've read posts ranging from changing out o-rings to go ahead and mix the stuff (maybe that was a joke). already bought the conversion kit and a can of solvent to flush out the old r12, and i will proceed as soon i figure out how to disconnect the lines, etc.

[George_Jetson]

First you would want to see if there is a leak. Once you have determined if the system is leak tight, you will need to drain the oil from the compressor, change the acummulator and expansion valve. Flush the system . Of course you will want to replace any gaskets / orings that are at any fitting that has been disconnected (I would not bother replacing all seals). Add the appropriate oil, evacuate the system, and then re-charge. It is not very hard, but requires speciallized tools that are not practical to purchase unless you do a quite a few systems. You could find someone on craiglist or similar and work with them while they do your car. But for a beginner, it is not practical to do it yourself.

I converted my 93, and although it is not quite as cold as original, it does a good job cooling my car down here in Texas.

[CornTaters]

First you would want to see if there is a leak. Once you have determined if the system is leak tight, you will need to drain the oil from the compressor, change the acummulator and expansion valve. Flush the system . Of course you will want to replace any gaskets / orings that are at any fitting that has been disconnected (I would not bother replacing all seals). Add the appropriate oil, evacuate the system, and then re-charge. It is not very hard, but requires speciallized tools that are not practical to purchase unless you do a quite a few systems. You could find someone on craiglist or similar and work with them while they do your car. But for a beginner, it is not practical to do it yourself.

I converted my 93, and although it is not quite as cold as original, it does a good job cooling my car down here in Texas.

I ended up going to an auto hvac shop in town to initially evacuate and keep the remaining r12 in exchange for the labor cost, but found out that the system was totally empty (after sitting in the garage for a year). I ended up paying $40 (or $6/oz. to recharge with r12) for the shop to suck out all the residual r12 which in turn created a vacuum of some degree. i immediately went home and installed the retrofit valves and the r134, and then there was cold air and no more code 23. About a month later (today) i took it for a short drive and no ac. Got home, held down the auto and recirc buttons and code 23 appeared. The gauge showed about 15-20psi, i recharged to 45psi, and all is well for now, as i finished using up the original r134 from the retrofit kit. So at this point i'm going to buy r134 refrigerant that has a dye in it, and nickel and dime the car once a month until i get the leak fixed. By the way the r134 isn't as cold as r12, as we all know, but it's more than adequate for spring weather. We'll see how it fairs in August when it's 110 degrees plus in the central CA valley. As always i'm open to suggeestions. Thanks y'all.