[RacerZack]

i posted this on another forum and didn't get much of a useful reply, so maybe someone here will have a clue what's happening...

on my '94 (which was the first year of the newer coolant), i've noticed that the A/C does this weird hot/cold thing. it'll blow cold air at first, but then sometimes the cold air will turn hot. at first, i thought it was related to the engine getting warm -- on super hot days, i'd notice the engine temperature go up and then the A/C would switch to hot. if it always behaved that way, i could understand that the system is sacrificing passenger comfort for engine temperature. (although i wouldn't be entirely "thrilled" if this was an intentional design feature)

the problem is that it doesn't always behave that way. sometimes, the engine will appear to be in the typical temperature range and yet the A/C goes hot. then, for what seems to be no reason, it'll go cold again. when it's cold, it does get cold like it should (not just "cool")....

naturally, this annoys me the most when it's friggin' hot outside and i'm wanting whatever cold air i can get out of the A/C. this has happened on and off for a long time (years). i know i've had dealers and mechanics look at it in the past and the typical test is for them to start the car, turn on the A/C, and then measure the temperature coming out of the vents after x minutes. under THAT scenario, it always returns a proper result of cold air.

not a real "mod" kind of question, but any suggestions would be appreciated!

 

[ExHondaMan]

Sounds like your compressor isn't holding its charge. Figure around $400 for the part, no labor. Is $400 worth of cool air worth it for another couple weeks? Thats the dilema i went through before deciding to hold off. The A/C is getting ripped out soon!

 

[renesisdrms]

maybe a/c compressor clutch is slipping? or maybe poor contact that grounds the compressor clutch. any hissing noise when the compressor clutch cycles? and does the cool/hot temp adjustor lever actually close the water circulation valve? might want to check if there's not a snap on the line.
if you want to isolate the problem... first check the coolant. is it fresh? flushed? only you'd know.
and then follow other checks. like components functioality... no compressor leak?(get a leak detector dye kit) and make sure there's full charge in your system. and of the right one.meaning, don't top off with R134 refrigerant if your system has not been retrofitted to accept R134 and can only use R12.
R12 has same size fittings and R134 has bigger fitting on the hot side.
and then see if you have no shorts or extra resistance in your wirings to the compressor...like kinked wires, torn, corrosions..etc. and then this is the hard one. check the compressor clutch disc itself...but if there's a oil leak, most likely your clutch disc is gone due to contamination.

all is very costly...unless you can diy.but if you can't. knock out the first few checks as they may be potential harm to your engine if lets say...the coolant was never changed.

 

[renesisdrms]

i'd check the heat/cool lever first. turn all the way in one direction,check to see if the lever actually closes the bypass to your heater core, then turn other way, see if the lever moved.