Battery replacement causing warm AC?

awright2009 · October 4, 2020

So recently replaced my battery for the second time, walmart battery died after 4 years, but was pro-rated for the 5 year warranty. Did a pretty smooth job changing the battery if I do say so myself (much easier this time around with a handle on the battery)

After taking a longer trip today I noticed that the air conditioner is blowing warm, the timing seems suspect with the battery recently changed, but maybe the changing weather here in Texas caused it to slowly leak the refrigerant out.

I checked the two fuses under the hood, think 56/57 or some such, and tried turning the key on and off a bunch of times (something about the electric vent motors losing position with a battery change)

Looking at the compressor, it's spinning, and I see no obvious signs of a leak, I did add that little support bracket to the lower AC arm as a preventative measure, but got the truck at 38k and have never had an AC problem. At 115k now and am kind of happy it's happening right as we enter the winter season

Any ideas? Battery change a red herring? Do I just need a recharge? It went from fine to nothing really quick, which to me means a very bad leak or a fuse someplace

rav3 · October 4, 2020

You situation does sound very coincidental to me too. I recall something like this happening to out '04 Trailblazer once when the power was removed one time. It ended up being an actuator, not allowing the cold air in or allowing hot air in. Here's what I would do to start.

1. With truck running & A/C on, check the A/C low pressure line, under hood on passenger side, and feel to see if it's cold. If it is, your compressor is working & would pretty much eliminate a total loss of refrigerant.

If that works, I would suspect that one of the actuator units got out of synch. & it's not allowing the cold air from the cooling coils into the cabin. Watch this video to understand what I'm talking about.

https://youtu.be/GoNNYWpZm_M

JimCost2014 · October 4, 2020

1 hour ago, awright2009 said:

So recently replaced my battery for the second time, walmart battery died after 4 years, but was pro-rated for the 5 year warranty. Did a pretty smooth job changing the battery if I do say so myself (much easier this time around with a handle on the battery)

After taking a longer trip today I noticed that the air conditioner is blowing warm, the timing seems suspect with the battery recently changed, but maybe the changing weather here in Texas caused it to slowly leak the refrigerant out.

I checked the two fuses under the hood, think 56/57 or some such, and tried turning the key on and off a bunch of times (something about the electric vent motors losing position with a battery change)

Looking at the compressor, it's spinning, and I see no obvious signs of a leak, I did add that little support bracket to the lower AC arm as a preventative measure, but got the truck at 38k and have never had an AC problem. At 115k now and am kind of happy it's happening right as we enter the winter season

Any ideas? Battery change a red herring? Do I just need a recharge? It went from fine to nothing really quick, which to me means a very bad leak or a fuse someplace

By the looks of your truck, it is a 14 or 15, which leads me to believe your condenser just went belly up.

awright2009 · October 4, 2020

Yeah, it's a 2014 and I'm beginning to think it might be the condenser, might as well change the condenser to AC compressor hose too for the better designed one that doesn't need a bracket at the same time I guess. I would change these out myself, but I don't have a vacuum pump and if you get garbage in the AC system it can cause lots of problems later. So I'll take it in to the dealer next weekend and have them do it.

Just held the high pressure / low pressure lines after starting up, small tube gets a little warm, big tube gets a little cool, but not really cold and not really hot, so I think it's working a little bit at least

When changing the battery I did kind of push the cover/box/ground cable towards the AC lines, maybe I bent it a bit or something

In terms of fuses/relays I checked:

https://www.autogenius.info/chevrolet-silverado-mk3-third-generation-2014-2015-fuse-box-diagram/

Driver side fuse box:

22	Heater, Ventilation, and Air Conditioning/ Auxiliary Heater, Ventilation and Air Conditioning Ignition

Under the hood

35	Air Conditioning Compressor Clutch

56	Air Conditioning Compressor/ Battery Regulated Voltage Control
57	Air Conditioning Compressor Module/ Battery Pack

68	Air Conditioning Control (This is a relay, swapped positions on it with another one that looked like it, no change)

Edited October 4, 2020 by awright2009

JimCost2014 · October 4, 2020

1 hour ago, awright2009 said:

Yeah, it's a 2014 and I'm beginning to think it might be the condenser, might as well change the condenser to AC compressor hose too for the better designed one that doesn't need a bracket at the same time I guess. I would change these out myself, but I don't have a vacuum pump and if you get garbage in the AC system it can cause lots of problems later. So I'll take it in to the dealer next weekend and have them do it.

Just held the high pressure / low pressure lines after starting up, small tube gets a little warm, big tube gets a little cool, but not really cold and not really hot, so I think it's working a little bit at least

When changing the battery I did kind of push the cover/box/ground cable towards the AC lines, maybe I bent it a bit or something

In terms of fuses/relays I checked:

https://www.autogenius.info/chevrolet-silverado-mk3-third-generation-2014-2015-fuse-box-diagram/

Driver side fuse box:

22 Heater, Ventilation, and Air Conditioning/ Auxiliary Heater, Ventilation and Air Conditioning Ignition

Under the hood

35 Air Conditioning Compressor Clutch

56 Air Conditioning Compressor/ Battery Regulated Voltage Control

57 Air Conditioning Compressor Module/ Battery Pack

68 Air Conditioning Control (This is a relay, swapped positions on it with another one that looked like it, no change)

If you have not had it done, have them check the Vacuum Pump while they are at it, known to fail on the early trucks too.

awright2009 · October 11, 2020

Trucks at the dealer now, although it turns out you can rent the vacuum pump at autozone and vacuum + recharge yourself. I’ve done a lot of adding r134a to my old truck but never had a vacuum pump, and I think adding too much refrigerant can be as bad as not having enough. Plus a good vacuum is needed or you’ll have air and moisture in the lines. Seems like something easy to screw up.

But the guy there looked through the grill with the flashlight for two seconds and confirmed it was the condenser. It would be nice if GM told you of these things while you still have warranty though

JimCost2014 · October 11, 2020

1 hour ago, awright2009 said:

Trucks at the dealer now, although it turns out you can rent the vacuum pump at autozone and vacuum + recharge yourself. I’ve done a lot of adding r134a to my old truck but never had a vacuum pump, and I think adding too much refrigerant can be as bad as not having enough. Plus a good vacuum is needed or you’ll have air and moisture in the lines. Seems like something easy to screw up.

But the guy there looked through the grill with the flashlight for two seconds and confirmed it was the condenser. It would be nice if GM told you of these things while you still have warranty though

Sorry, was not talking about the AC system, should have been more clear:

awright2009 · October 11, 2020

Nah I was just talking about replacing the condenser myself. I’m assuming you mean the brake vacuum? Not too sure about this separate belt driven pump (used to the giant cone shaped brake boosters) But I figure if that ever goes out I can 100% do it myself, shouldn’t be too bad I would think

I’ve done master cylinders, brake boosters, and bleeding on different vehicles etc Just never anything serious with working the AC other than charging the system, but never really looked up how to work the AC manifolds properly before now

Dinkee · September 24, 2022

I had the issue when we had to jump start my truck. I had my brother in-law who is a gmc mechanic take a look and he noticed that the bolt that is on the compressors clutch was missing so we replaced that and now my air is blowing cold again p