GOd it's so hot please help with my A/C problems. :(

[Justin@JDM]

I have exhausted the search button out and can't seem to find anybody with the same kind of symptoms I am having with my A/C system so I'll start from scratch....

My A/C works fine and blows cold air ONLY when I hear a chirp about every 6 seconds from the front of the motor. It will only chirp when the A/C is on, but after about 5 minutes of it working great the chirping will stop and it will blow hot air. When it stops chirping and starts to blow hot air I can try to rev the engine high and I will hear the chirp again and the A/C will work fine only for a shorter amount though. If I am at idle forget about it, hot air only and no chirp.... I ruled out belt slippage because the chirp is very consistant at about every 6 seconds. I'm thinking it's the clutch but I'll leave that up to you guys to help me out.

Thanks for any help its getting very hot outside..

Justin

 

[Ishodu]

Sounds like your belt is slipping some, and 90% chance your charge is getting low. Once it starts compressing the gas its going below the minimum pressure and cuts the AC off. This is why it would cycle like that. You could grab a gauge and hook it on the low pressure side. (up near the firewall) and see what your getting for a low pressure when the compressor is running. Btw what year is your car?

 

[Justin@JDM]

So, how can I rule out belt slippage? Replace the belt or tighten something? My SHO is a 1992. How do I go about testing the pressure and knowing where it should be at?

Thanks for your help!!!!

 

[DHMag]

i believe its either low charge, faulty pressure switch, weak clutch.

 

[Justin@JDM]

So what order of steps (cheapest first lol) would I take to troubleshoot this.

Thanks guys...

 

[DHMag]

the switch is ~$20 at your local parts house. im not sure if these can be tested. im sure theres a way but ive never looked into it, given the cheap price for replacement.

a tire gauge style pressure gauge is relatively cheap at your local parts house as well. check the low side only. for the life of me, i can not recall what the reading should be at the moment. **EDIT** 25psi clutch engages, 45-50psi clutch disengages.

visually check the clutch plate. if its less than .095 thick (estimated), it could be heating up and disconnecting from the pulley. equally, check the pulley face what you can see). if it shows a lot of blue or gouging, it can cause weak connection. if both look good, check the gap with a feeler gauge. gap between pulley face and clutch hub should be .030". if its more itll cause the clutch to disconnect. too small and itll create enough heat to shred a belt. you can reshim it by removing the clutch hub nut and clutch hub. there are small/thin washers on the threaded shaft. these are used to distance the hub from the pulley. a replacement clutch is your most expensive route, averaging about $90 at your local parts house.

 

[Redskull]

not to sound like a cynic, but if your SHO is R-12 you might as well get used to 4WD a/c. I tried to fix my 89 A/C, and kept finding that every part I wanted to replace involved replacing two others, and to do it right would eventually involve replacing all the parts :banghd:. It won't be cheap and it won't be easy

alan

 

[rangerj]

Before you replace the low pressure switch disconnect it and jumper wire the connector. If you get the same symptoms then the switch is not the problem.

I agree with the guys above. Measure the gap between the clutch surfaces. A gap that is too large will also cause the clutch to fail to stay engaged. The gap should be .025 to .030.

If the gap is not greater than .035 to .040 then this should not be the problem. Given the age of the car, and the low refrigerant pressure symtoms, I think you are low on refrigerant charge.

Here's the problem with that. Your 1992 has R-12 refrigerant in it, unless it had been converted to R-134a, and that refrigerant sells for about $225 per pound. Your system takes about two pounds (32 to 36 ounces).

You can convert to R-134a, which is about $20 per pound.

Let us know what you find out and what you want to do about it.

 

[Justin@JDM]

What would be associated with the chirping noise that I am hearing than?

 

[I'll sho u]

You are probably hearing the clutch cycling. If there is any rust on the clutch face it can sometimes make a real racket when it engages.

 

[caseywan]

I have been having a lot of AC problems lately on both my cars so I have been doing a lot of reading and researching and to me it really sounds like the freon is just too low and that is why the clutch is kicking on and off.

***There is a lot R-12 sells on ebay, and they all say that you have to have a license to purchase, BUT there are many sellers on ebay that will sell to you if you just tell them either that you are buying it to resell it or for your licensed mechanic to put in your car. You just have to email and ask different sellers. I just bought some R-12 off ebay this way. I now of one seller in particular that sell to you if you tell thim this, his user ID is ahappybuzzard, and here is a link to the freon he has for sale right now.

http://motors.search.ebay.com/_W0QQsassZahappybuzzard

They are 2 pound cans and they go for less than 50. I would definately look into keeping R-12 because it lasts longer and blows colder. And to really do a conversion to 134a the correct way you would need to have it professionally done because most those $30-$40 "do it yourself" conversion kits don't last.

 

[Justin@JDM]

Ok, I got my hands on some R-12. I posted a new thread asking if this is something I can do myself and if so does anybody have some step by step instructions.

Thanks!!

 

[econ]

The chirping noise that you are hearing is call locked rotor in the hvac world. The compressor is actually freezing up. If you have air coming out below about 55-60 degrees than your charge is low and the clutch will kick in and out. you can get a 134a recharging gauge and filler all in one at the parts store along with 134a for about 12-15 dollars a can in it only takes about three if you are completly empty