A/C not blowing as cold as it should

[porschpow]

Thanks to the help of Vicky, I managed to get my A/C running on my 89 townie, however, these passed few days, I had noticed that it is blowing cool air, not cold as it should. The weird thing is that weeks before when I let the car run for a while with the A/C on, it was COLD!!!


I can hear the compressor kicking on, so it's not like the compressor is crapping out.

Anyone ever dealt with this?

[sly]

check to make sure the evap is getting cold (the dryer should be cold as well - so just checking that should be good enough). If it's still good, then you may have a broken blend door to deal with (remove air plenum and rebuild the blend/vent doors with piano hinges). If it's not getting cold, you may have a bad/blown orifice tube that needs replaced. You could also have a restriction somewhere else and if you find something else to be cold on the system (like half of the condenser) the clog will be there and that would be preventing the system from working right. The compressor may not actually be compressing good (blown seal on a piston or 3). Putting a set of gauges on the system will figure that out. Rule of thumb for that is the high side should be about 3x ambient temp for the orifice tube system in the panthers. If it's +/- 10% you should be fine. If it's really high (like over 350psi), your radiator fan is not pulling enough air or there's a restriction in the condenser. If the high side is low (below 180psi with the low side constantly over 30psi), the compressor isn't compressing well, or the orifice tube is blown.


This is all assuming the compressor isn't short cycling due to insufficient refrigerant.

[porschpow]

check to make sure the evap is getting cold (the dryer should be cold as well - so just checking that should be good enough). If it's still good, then you may have a broken blend door to deal with (remove air plenum and rebuild the blend/vent doors with piano hinges). If it's not getting cold, you may have a bad/blown orifice tube that needs replaced. You could also have a restriction somewhere else and if you find something else to be cold on the system (like half of the condenser) the clog will be there and that would be preventing the system from working right. The compressor may not actually be compressing good (blown seal on a piston or 3). Putting a set of gauges on the system will figure that out. Rule of thumb for that is the high side should be about 3x ambient temp for the orifice tube system in the panthers. If it's +/- 10% you should be fine. If it's really high (like over 350psi), your radiator fan is not pulling enough air or there's a restriction in the condenser. If the high side is low (below 180psi with the low side constantly over 30psi), the compressor isn't compressing well, or the orifice tube is blown.


This is all assuming the compressor isn't short cycling due to insufficient refrigerant.

Awesome. Thanks. But I didn't know box townie's had blend doors.

[DerekTheGreat]

Everything has blend doors lol.
But yeah, sly's advice is on point. All I have to add about the fan not pulling air is to check if there is any build up of gunk between the radiator & condenser. There was a shit load of leaves in between my radiator & condenser on my Ranger. Got that cleared up and was good to go.

[gadget73]

They do. The HVAC system is virtually unchanged from 1980-2012. The only real change is in 1990 when it changed to an electric motor to move the blend door. Boxes use either a cable or a vacuum motor to do it.

[porschpow]

gotcha, GADGET! The air conditioned guru! lol I was hoping to hear from you!

[porschpow]

When I hook up the freon can, the gauge jumps up and down from 30-35 to 50-55 psi in sync with the compressor turning on and running for 4-6 seconds at a time

[DerekTheGreat]

You need the real gauge set, need to know what the high and low side are doing like sly mentioned. The Mickey mouse stuff won't cut it here

[sly]

Standing pressure (AC OFF) should be at around 90 psi from what I've seen with my cars.

[porschpow]

Yeah, I need to get the manifold gauge kit.

Well after a day, i no longer have cold air. I am sure it leaks somewhere. I put the dye in it, I just need the dark to see where it could be. The the compressor doesn't even engage!

[sly]

yep. probably a leak then.

[porschpow]

Is there a common spot where boxes leak, or is ever car different?

[jaywish]

You probably need some 134 in there to get the compressor pumping which will distribute the dye to the leak.

[porschpow]

i used the rest of my r-134a followed by these dye shots that you pump into the system. the system was betweeen 45-50 psi @ 83 degrees F. However, I had issues using the UV light to find the leak

[gadget73]

Could be anywhere. I've had a lot of trouble with leaks at the charge ports, but any connection points are a possible issue. I've replaced a condenser in my Towncar, John has done several evaporators. I once had a compressor lose a shaft seal. Basically it depends, you just have to seek and destroy the leak.