1988 Coupe A/C Help

[Bonnell]

Hi Everyone,

My A/C hardly cools at all. I had the unit charged several months ago and they replaced the schrader(sp) valve as part of the service.

The suction line gets very cold and the compressor does engauge but it only stays engauged for a few seconds and then turns off. It cycles like this and does not do a very good job of cooling.

There is a company in Little Rock that specializes in auto air. One of the students from my college works there and they seem to be quite a bit less expensive than a dealer.

He indicates that there is a cycle switch on that car that could be bad and it is cheap. I assume that the short cycling would also result from a low charge (true/false?).

Anyone heard of this? Any other ideas?

Thanks,

J

 

[FrankM]

cycling like yours is usually a sign of a low charge. do you have R12 in it?
take a pressure reading to verify switch is operating normal.

 

[Bonnell]

I was afraid of that. The tech at the auto air shop said that they could inject a dye to see where the leak was.

I don't have gauges and the Chilton manual that I have won't delve into the A/C system so I am at a loss as to how to go into the checking of the pressure.

Is there a common area where leaks occur in an '88?

Thanks!

 

[FrankM]

Is there a common area where leaks occur in an '88?

Thanks!

AC condenser where the inlet and outlet connect. look for oil stains

 

[Moonunit 451]

I agree, low chargead . I'd take it back and see if the guys that charged it will take care of you. Make sure they checked for other leaks in the system, besides the valve they replaced. They should be able ot check the current charge and for leaks with a "sniffer" fairly quickly. Another leak could have developed in the system, but they may have made an error in the initial service. Good luck. A community collage with A/C courses (if you know someone) would be a reasonable alternative. Is it R12 or R134? It's R12 unless you or someone else had it converted.

 

[Moonunit 451]

A dye should not be neccsary, look out

 

[Bonnell]

As far as I know, it is R12.

Thanks for the advice. I'll see what the dealership has to say about the charge.

Now, if we can just get the hood open...

 

[Moonunit 451]

I haven't converted to R134 yet, but if you need a recharge you might consider it. R12 is getting REALLY expensive. R134 is said to be a good alternative, but I can't confirm that. The conversion isn't all that expensive. Make sure you get paid or credited for any R12 recovered (by the pound or OZ) if you convert. Federal law prohibits anyone servicing A/C without certification and a proper recovery system. The R12 is a valuable commodity.

 

[Eagle85C4]

To become certified you can take the open book online test for EPA section 609 MVAC. Cost 20.00 at www.qwik.com well worth your time...

 

[Bonnell]

I may well take that test. I think that it may be worth it in the future.

Thanks!

 

[Bonnell]

I took my car to an auto A/C shop this morning and they added a little freon (he said about 1/4lb) and only charged me $44. The chevy dealer charged the system in November and charged me $138!(?)

Thanks again for the help.

J

 

[FrankM]

well at $44 for 1/4 of a pound,
1 pound = $176

Kind of steep.

now if the chevy dealer installed 2 3/8 pound for $138 I would say that is a better deal.
1 pound = $58.08

good deal.!!

 

[vigman]

Is the main fan ON!

When A'/C is engaged?

Take a look there first!

I MIGHT have a trick for you..

Does the AC work better when your moving?



Vig~

 

[Bonnell]

Do you mean the radiator cooling fan? If so, yes, it comes on. In fact, yesterday I was driving (about 83 degrees, low humidity) around town enjoying the day - topless of course - and I noticed that the cooling fan came on and stayed on as the temp pretty much stayed at 229 while in town. It does seem that the cooling is better at higher speeds but that may simply be the cooling effects of the wind on me.

Summer will be much warmer - I wonder if I should get a chip to turn the fan on at a lower temperature?

What is the trick that you have in mind?

Thanks,

J

 

[Bonnell]

Thanks for the reply.

Is there no oil replacement or anything else needed for thr R-416A? Can I get R-416A at a normal auto parts store?

I used to work on A/C a long time ago so I'd like to be able to start working on my Vette with the A/C if needed.

The shop checked for leaks but found none.

Thanks again,

J

 

[FrankM]

Thanks for the reply.

Is there no oil replacement or anything else needed for thr R-416A? Can I get R-416A at a normal auto parts store?

I used to work on A/C a long time ago so I'd like to be able to start working on my Vette with the A/C if needed.

The shop checked for leaks but found none.

Thanks again,

J

I bought some at Pep Boys last year $35 a 12 oz can

Pep Boys in Auburn, Maine had it.

They don't use much AC there.

 

[Bonnell]

Well, if you can get it in Maine, I should be able to get it in Arkansas.

I'll try Pep Boys. Thanks!

 

[FrankM]

Well, if you can get it in Maine, I should be able to get it in Arkansas.

I'll try Pep Boys. Thanks!

You will need to show your license

 

[vigman]

The trick ( c-4 AC fan lock on)

Most of the time the c-4 High side switch breaks.. this is the signal for the ECM to know YOU have selected AC.

As the AC is turned on you need MORE air going over the evaporator.. the ECM monitors the high side ( with this switch ) and turns the fan on.

If you do not get the needed air over the evaporator.. the clutch will cycle on & off as the pressure rises and falls.( seperate circut )

Trick...

IF the MAIN fan doesn't kick on after 4 seconds ( roughly ) AFTER the compressor is rolling... do the following.

On the HIGH side pipe ( small one ) near the firewall there is a SMALL( pressure) switch with a two pin connector( Dark Green & Black wires)

Pull it!

The fan should run constantly! ( except when you go faster than 40 mph.. and it shuts down..different circut again)


Try it!

Vig~