Hello all,

I own an 87 Camaro and I recently renewed all of the air conditioning components (compressor, drier, condenser, orfice tube) with the exception of the evaporator core which I flushed. After pulling a good hard vacuum and charging (r134) the system, it cooled well. A couple of days later, I started the car and after a couple of minutes idling, some of the refrigerant blew from the compressor from some check valve, I'm guessing.

It has done this twice to me and i cant figure out why. The only thing i can think and i don't know if this is even valid, but when i start the car and engage the air conditioner, none of the fans start to operate. Could this be the cause? Do your fans start immediately when you engage the air conditioner?

One other thing, i replaced the small round connector that plugs in to the top of the compressor in the back, would that have anything to do with this issue too?

Help!

James

 

how much fridge did you add? that switch is a cutoff switch if pressure is too high it will turn everything off. you can put ohm meter on it to see if it reads zero or infinity. zero means normal. otherwise your ac will not turn on

 

Blue i added what the system required; the second time i took it to a repair shop and they added what it required as well. I cant remember how much. Anyway, the only thing i can think is when i took the car, the engine was hot and the fans were running. The ac cooled well and everything was fine when i parked the car. The days later, the engine was cold, no fans running when i activated the ac and that's when it popped! I'm thinking of taking it out today and running it and once its hot, turning the ac on and see what it does. Process of elimination, if you will.

 

Well I took it out and drove it for a bit so that it would heat up and when i turned the ac on, it worked fine. I don't know what the hell is going on!

 

if the AC dosent get enough cooling when running (i.e. no fans)it overpressureizes and the relief valve in the back of the compressor opens and let's some pressure off, u need to get those fans going and replace what coolent/oil u lost

 

Sounds good!
So my questions:
When I activate the AC, are the fans supposed to immediately turn on with the compressor?
If so, what sensor do i need to check or replace?

Thank you,
James

 

unfortunately mine was a factory mechanical fan, and I have my electrics wired to come on when the temp exceeds a certain point (IIRC 185) or when the AC is on(AC overrides the thermostat)

 

im no expert, but it seems this would be against regulations. it should shut down the compressor for sure, but blow out freon? are you certain?

 

I think they were thinking it's better to vent allitle off than the whole thing vent out

 

Hmmm...My 84 carb HO the single fan starts up and kicks up the idle when you slide the lever to
any a/c selection! The refrige juice blowing off is not normal tho.

 

I'll be playing with the a/c later today. will let you know how my fans behave. I know for certain if the engine is warm enough, the 2nd fan will kick in when a/c turned on. just not certain what occurs when engine is colder.

if you look further down in this thread, you will see some wiring diagrams that may help you. https://www.thirdgen.org/forums/cool...h-mounted.html

 

FWIW, when mine is dead cold start and A/C is switched on, cooling fan comes on immediately.

 

The stock set up has a high pressure switch on the compressor (I think this is what you are talking about here) and a low pressure switch at the dryer, Assuming you are building too much heat (and thus pressure) in the system one would think the high pressure switch would shut the system down before it reached the blow off pressure. The high pressure switch only exists to turn off the clutch in case of high pressure, it doesn't drive the radiator fan.

Best advice would be to buy a set of gauges from harbor freight or other cheap tool vendor and see what pressure you are getting to. It could be that you are actually over pressure or the blow off valve is bad and venting at a low pressure. You could be hitting a pressure in which the outer ring seal is leaking on the compressor and not the valve. You could have a faulty high pressure switch/wiring. At the very least get the radiator fans working as they should.

 

For the stock dual fan setup, there were two designs. A 1987 only setup. And the 1988-92 setup.

The '87 setup is that when the A/C is turned on, it automatically turns on the primary (driver) side fan. Regardless of coolant temperature.....But the secondary (passenger) fan only turns on at 235°F coolant temp. This means that driving around town with the A/C on, you will have definitely the driver side running. You might have the passenger side on. But only if it gets the coolant temp up in that high range. (traffic jam/heat wave)

The '88-up setup automatically turns the driver side fan on when the A/C is on. But it also turns on the secondary fan at 233 psi (high side A/C pressure) or 235° coolant temps. Whatever happens first.

The reason for this is obvious. The 87's were crippled for A/C performance because most of the time only one fan would be on. The newer cars more often than not, both fans would be on anytime the A/C is on. There are exceptions. Idling the car in the driveway when it's say 60° outside, you will see the passenger fan cycle on (233 psi) and then cycle off (180psi) even though the coolant gauge hasn't even moved yet. Driving the car on mild nights with no traffic when you just want to dehumidify the air, the secondary fan can be off when the A/C runs.

I would recommend changing to a lower fan temp switch for the '87 cars. This will activate that secondary fan more often and pretty much turn it into an '88 setup. They're not a bad idea on the 88-up cars either.

 

Thank you, Reid,

That’s what my understanding is on this dual fan setup.

What I’m trying to figure out is why do both the driver and passenger side fans turn automatically only when the coolant reaches high temperatures? If I idle the car in the driveway with the A/C turned on, after a few minutes the cold air becomes hot and next, some of the refrigerant is discharged from the compressor relief valve. As is mentioned before, now if I run the car to the point where the fans are turned on and then I turn on the A/C, everything works well.

I need help figuring out why the fans aren’t operating as they should;

1. Why doesn’t the primary (driver) side fan automatically turn on when the A/C is turned on regardless of coolant temperature.
2. Why doesn’t the secondary (passenger) side fan turn on when the coolant temperature reaches high temperatures.

I read some of the links previously posted where it shows wiring diagrams and to me that's like reading a foreign language. I can do minor mechanic work, but I don’t know squat about electricity, wiring on cars or how to read wiring diagrams. There has got to be a stupid simple way for me to understand so that I can figure this out, videos, hands on stuff.

Any and all help is greatly appreciated!

James

 

https://www.google.com/search?client...6ItQXyw5CACg32

 

The above search will give you many options on how to learn how to test continuity. Reid had already answered the last question you asked, go back and read his post. Slow down, process the info, and write it down on some diagrams to help yourself understand better.