ac runs cold for three minutes then warm

[brus brother 131]

2005 Outback AT 190k miles.

Started yesterday 90 degrees out. AC runs nice and cold for the first 3 minutes then blows warm air (same as outdoor air). Turned engine off for a few minutes, restart the car and same sequence, runs cold for 3 minutes then warm air.

[forester2002s 124]

Maybe the compressor clutch is disengaging after 3-minutes.

Can you see if the compressor is turning (not the pulley, which turns all the time, but the clutch-plate in the center)?

And does the AC indicator-light stay on?

[moosens 403]

Crosstrek , Jim. You deserve one. And you can likely afford one. ;)

Your 12+ year old car can help somebody who can’t afford a new one. 

Otherwise I’d say you just need a recharge. But I know way too little about an actual 2005 anything. 

Good luck man ! That lovely humidity is back. 

[brus brother 131]

AC light on

 Clutch not spinning.

[brus brother 131]

Hey moosens. Some respect for the elderly. Bought that 05 in the summer of 04 so it's 15 years old. Leaks plenty of oil... Need your driveway resealed, I'll drop the car off.

 

[forester2002s 124]

2 hours ago, brus brother said:

AC light on

 Clutch not spinning.

AC light on usually means charge is OK.

Does the clutch spin at startup, and then stop spinning after 3-minutes?

[brus brother 131]

1 hour ago, forester2002s said:

AC light on usually means charge is OK.

Does the clutch spin at startup, and then stop spinning after 3-minutes?

yes

[forester2002s 124]

Could be that the clutch is failing for some reason.

Perhaps it's engaging at start-up, and then starts slipping/overheating?

Two options:

1. adjust the clutch (search on this forum for previous posts); or

2. get another compressor (perhaps a used one from a bone-yard).

[brus brother 131]

Not just a matter of low on freon? I was hoping...

[heartless 422]

if it was low on freon it wouldn't get cold at all.

 

[1 Lucky Texan 888]

has it been recharged in the past? 14 year-old car could EASILY be low on refrigerant.

 

[brus brother 131]

Lucky T,

I think I may have recharged it once.

I just checked the gap for the ac clutch and it is spot on for spec. so no need to go rip that apart for now.

I am now leaning back to low on gas.

Will check and report back.

[NV Zeno 50]

Likely low on refrigerant.  Select the type of refrigerant that has lubricant included.  Be careful not to overcharge.

 

My 2 bucks

[brus brother 131]

5 minutes ago, NV Zeno said:

Likely low on refrigerant.  Select the type of refrigerant that has lubricant included.  Be careful not to overcharge.

 

My 2 bucks

Inflation!

[brus brother 131]

I am guessing that I am now reqally low as the clutch won't engage now. Problem is how to refill without ac running.

Bypass the relay?

OK never pulled a relay  out before. I have identified the relay. Is it just a straight pull out or is there a retention clip that needs to be pushed back?

Then, what terminals do I cross to bypass the relay?

[brus brother 131]

ok may have figured out the mystery. If I wiggle the relay the clutch spins in and I get ice cold air. Possibly the relay is the problem? Is the symptom of a dying relay that they fail after a short period of time working? Can failure be intermittent like this where they fail after working for a few minutes and then start again after rest??

[1 Lucky Texan 888]

I use manifold gauges, 'borrow' a vacuum pump from the parts store (dunno if they loan out gauges) and pull a vacuum for a while, then turn off the pump and monitor for a leak, if all looks good, close the valves, remove pump, attach a refrig can, open it, pop the valve athe top of the center hose to clear atmo air out, then, open both valves. The vacuum will pull a LOT in. Then, close the high side valve and start the car, likely there's enough in now to satisfy the low press cut-out and the comp. will pull in. Then, after the first can is empty, I attach the second can. It seems to help to boost thr rpms a few times to 2000 or so, for a several seconds. Our Outback has a label on the rad frame in front of the compressor that says something like 22-26 oz so, 2 'regular' cans is what I put in. If you are just going to try to add to a closed system, maybe just see if enough will go in?

 

this is why most people use a pro for this stuff. Even when I do it now, I have to triple check myself as the procedure is so involved. Add to this trying to fit o-rings or valve inserts, leaking hoses (I've had 3 - only one under warranty way back) and folks reporting bad rev sensors, or weak relays (swap yours with another one that's the same - maybe headlights???) and taking shims out of clutches......it can get crazy.

 

you might look around here;

 

Edited July 10 by 1 Lucky Texan

[brus brother 131]

Lucky T,

When I put the gauge on the system (Parts store gauge and can Arctic Freeze) it showed full.

As I thought I was going to have to jump the relay to get the clutch to engage, and suck in the gas, as I just wiggled that big honkin relay in the fuse box, the clutch started spinning.

The mystery of why there would be ice cold air then nothing seems to be explained by the failing relay?? Do relays fail like that where they work for a few minutes then cut out, as if heat expansion affecting performance.

Edited July 10 by brus brother

[1 Lucky Texan 888]

sure, they are electro-mechanical and can become intermittent, plus, older cars could have poor grounds and other connections....nothing is 'ideal' like when new and the weakest link fails. I wouldn't say it's common, but I have read of relays doing this 2-3 times in the past. Who knows, taking it out and re-inserting it might wipe a little corrosion from it's terminals and it could work for 5 more years, or, it has burned-off a contact internally and is just worn-out. They aren't expensive and just getting a new one is probably the best move. But, for further diagnostics or just to satisfy curiosity, swap it with a different relay of the same type. See if the problem travels with the relay. You could also spray a little contact cleaner in the relay's socket.

[brus brother 131]

Twas the relay $6 and all is cool again.

[heartless 422]

told ya it wasn't low on refrigerant, LOL

glad you got it sorted out and for cheap, too!

Edited July 11 by heartless

[moosens 403]

Can I bum that can of refrigerant off you ??! Lol 

just kidding. 

[brus brother 131]

Sure. Used some in wife's 08 and she is chilling now but some left in can.