Air Conditioner not turning on

I've had the car a couple weeks and visisted the dealership today for another issue and had them check it. It turns out there's a controller module (was called a ccrm on my old car) that's not allowing the AC compressor to cycle on. I was looking for some help on what/where it may be to replace it. Any help would be greatly appreciated....in the mean time, does anyone have a quick link to some vacation pics. I coulnd't find them earlier when I was looking.

Dragging up an older thread...

 

Im having similar issue - AC doesn't come on..

 

I've done a bit of troubleshooting as follows:

 

First checked the AC Fuse, good

Then checked the AC Relay, I can power up the relay and hear it 'click' and I can check continuity across the relay after power and circuit to compressor functions.

Checked the compressor solenoid by jumping the the AC Relay Socket, compressor engages.

Checked power on the AC Relay Socket and it is dead on all conditions.

 

So, checked the external temp sensor @ front bumper by looking at readout on the screen of the external air temp. It appears to be functional and raises and falls consistent with surrounding air temps. But I didn't pull it and check resistance.

 

Then checked the internal cabin air temp sensor behind the small vent at driver right knee. Pulled the sensor, cleaned with MAF spray. replaced.

 

No difference. The 'system' senses the need for AC b/c the recirc will come on to recirculate internal air and the fan will gradually bump up until it is full, but no cool air. So I'm looking at either 1 more sensor down in the console on the condenser, the sun sensor on the passenger dash, or at the control unit.

 

Does anyone see an issue with the troubleshooting as I've laid it out or have experience with this to point more toward the condenser sensor, sun sensor, or control unit? Basically the system is sensing the need for AC but there is no 'on' signal getting to the compressor. TIA for suggestions.

Are you certain the AC system has any pressure? Don't go digging into those other things without verify this 1st.

Are you certain the AC system has any pressure? Don't go digging into those other things without verify this 1st.

 

No, not certain. Is there a limit switch that prevents the compressor solenoid from engaging at low/no pressure? Its not that it doesn't make cold air, but the compressor doesn't engage.

 

If yes, stands to reason it could be the problem because the motor was out last fall and lines could have been cracked open but not refilled.

 

Thanks for the reply...

No, not certain. Is there a limit switch that prevents the compressor solenoid from engaging at low/no pressure? Its not that it doesn't make cold air, but the compressor doesn't engage.

 

If yes, stands to reason it could be the problem because the motor was out last fall and lines could have been cracked open but not refilled.

 

Thanks for the reply...

I can't speak specifically to any given vehicle but every air conditioning system I'm aware of has had a pressure sensor to ensure adequate refrigerant to ensure the compressor doesn't overheat due to low pressure.

I can't speak specifically to any given vehicle but every air conditioning system I'm aware of has had a pressure sensor to ensure adequate refrigerant to ensure the compressor doesn't overheat due to low pressure.

 

^This is correct, and on our car the AC pressure switch is screwed into a AC line on driver side, "kinda" below fuse box area. Just follow AC line on driver side of engine bay and you will find it. However the best way is to have a set of pressure gauges hooked up to car to check for pressure.

I concur with the posts above.. the most likely reason your A/c is not coming on is due to inadequate refrigerant pressure. You can get a cheap a/c low side gauge kit at autozone / pepboys and check it yourself.

I can't speak specifically to any given vehicle but every air conditioning system I'm aware of has had a pressure sensor to ensure adequate refrigerant to ensure the compressor doesn't overheat due to low pressure.

 

^This is correct, and on our car the AC pressure switch is screwed into a AC line on driver side, "kinda" below fuse box area. Just follow AC line on driver side of engine bay and you will find it. However the best way is to have a set of pressure gauges hooked up to car to check for pressure.

 

I concur with the posts above.. the most likely reason your A/c is not coming on is due to inadequate refrigerant pressure. You can get a cheap a/c low side gauge kit at autozone / pepboys and check it yourself.

 

Thank you all for weighing in... This is now my next focus. Will be checking it this weekend.

Ok, the input proved to be right-on. Low/no pressure.

 

I bought a $35 low side recharge kit with pressure gauge and followed the instructions. After a minute or so of filling the system, the AC clutch kicked in and began to produce cold air.

 

Thought I was home-free....

 

The Saturday morning, no AC - no pressure. I checked with Subaru dealer and the parts guy said yea, we keep the O-rings for the compressor onhand because they get 'squared' over time and just leak. Seems to happen more right after a cold winter. So I purchased a set of 3 O-rings from Subaru; inlet, outlet at compressor and the pressure switch. Replaced them. Recharged, compressor came on, Home-free, right?

 

This morning, no AC and the clutch would not engage. So back to no pressure. I refilled and quickly turned the car off and stuck my head all around and heard a little hissing. Following my ears, found a very small nick in the aluminum condenser in front. I could put my finger in front of it and feel a steady stream of air shooting out.

 

I picked up some liquid steel epoxy with like 4,200 psi tensile strength (!) and put a small blob on the hole after cleaning the area up well. Tomorrow morning after an overnight cure, I'll try again. Meanwhile, I've found replacement condensers on eBay for about $50-60. Priced them at local auto parts store for $150. If the epoxy doesn't hold, I'll be picking up one off of eBay. I can live with no AC for now, but summers in CO get up to 120F on a hot day...

 

On another note, does anyone have a recommendation on replacing the AC Drier? I believe this model has a cartridge that can be placed in a tube mounted to the passenger side of the condenser. Anyone done this?

 

Thanks again to all the good suggestions. Right on the money.

Glad you figured it out, hate to break it to you but I doubt the epoxy will last. And yes you need to change the drier. It just has 2 bolts in the bottom of the canister and you can change it, will be easy when the condenser is out for replacement. Also you really need to vacuum the system free of air after you replace those items.

Always wear eye protection around refrigerant. I went to school with a guy who was blind in one eye due to an accident which could have been prevented.

Glad you figured it out, hate to break it to you but I doubt the epoxy will last. And yes you need to change the drier. It just has 2 bolts in the bottom of the canister and you can change it, will be easy when the condenser is out for replacement. Also you really need to vacuum the system free of air after you replace those items.

 

Thank you for the advice!

 

To finish off the narrative above...

 

This morning I re-charged and tested AC - got cold air! When I turned it off - no noise and the epoxy seemed to be holding. Drove it and made cold air all the way.

 

Lunchtime - same - drove it and made cold air, no leaking yet.

 

Afternoon - same - drove it home and made cold air, so it hasn't leaked out yet. And I stuck my head in immediately on shut down and didn't see/hear anything amiss. So maybe this has fixed it, albeit temporarily. I'm going to drive it like this for a while. If it blows off the epoxy plug, I'll bite the bullet and pick up another condenser and drier and see about vacuuming out the system. Glad we have a harbor freight here...

 

Always wear eye protection around refrigerant. I went to school with a guy who was blind in one eye due to an accident which could have been prevented.

 

Great advice.. While searching the web for info on this, I noted the extra cautions about eye care. I usually wear a pair of protective glasses when working on cars. In this case, I had a pair of cheaters b/c the hole I was working on was tiny! Good advice for anyone.

 

Thanks again all. With my luck, this will work right up until that first 120F day.

Its been almost 2 weeks and the epoxy fix is still working.

 

Not wanting to make an hour drive around Denver in July/August at 115 deg, I went ahead and ordered a replacement condenser, drier, and picked up a venturi vacuum and a manifold gauge set from Harbor Freight with a 25% off coupon. So I'm set to replace the condenser next weekend.

my ac will most of the time work but if used for to long it may stop working. but after shutting the car off and trying later its back to working. i am thinking the ac clutch is starting to fail but really have no clue. all looks ok and i have spent no actual time trying to diag this very intermittent problem

my ac will most of the time work but if used for to long it may stop working. but after shutting the car off and trying later its back to working. i am thinking the ac clutch is starting to fail but really have no clue. all looks ok and i have spent no actual time trying to diag this very intermittent problem

 

That’s what mine is doing. It has been recently charged and leak tested but the compressor is still intermittently turning off after some use then working later after a rest. I guess the clutch or compressor is starting to go but I don’t know. Anyone else have this issue?

well my crank pully failed and messed some stuff up including the electrical connector to the ac comp. after replacing the pully and belts and rigging up the connector instead of a new compressor.... its been working great

 

edit.... also replaced my radiator recently and washed a lot of dirt out of the ac condenser.

 

try washing out your condenser. remove the 2 upper radiator brackets and tilt the radiator in and flush running water through the condonsor and also wash off any garbage from the radiator itself as well

That’s what mine is doing. It has been recently charged and leak tested but the compressor is still intermittently turning off after some use then working later after a rest. I guess the clutch or compressor is starting to go but I don’t know. Anyone else have this issue?

Check the relay in the engine bay. My went bad and the compressor would constantly cycle.