A/c help

[jbaker]

Clutch wasn't engaging....added some 134 to it.....compressor clutch now cycles on and off like every 5 seconds but only on for 2 seconds at a time....ideas?

 

[87GNSteve]

Did you have an AC pressure gauge when filling it?

 

[jbaker]

Yes..

 

[87GNSteve]

What was the Temp/Pressure?

 

[jbaker]

Ambient was 90*.....15 psi when I hooked up....I put in small amounts till compressor kicked on. Sitting at 50 psi and compressor pulls it down to 20 or so when it kicks on.

 

[jbaker]

Since I'm no expert here it will go to the shop if no one has any solutions I'm capable of doing....unfortunately they just serviced it last July and now it doesn't work....dah

 

[aminga]

what's the high side?

 

[jbaker]

Dunno, I was using what I had left from filling my s10 last year just to see if it was low and could get the compressor to come on. I don't have an a/c kit with all the gages. Prolly just drop it at the shop again :-(.

 

[gsgnnut]

Short cycling usually means not enough freon. Need to have gauges to properly diagnose.

 

[87GNSteve]

Yes sounds like low Freon.

 

[theCATman]

Low side with compressor on needs to be minimum of 30 psi.

Unplug the low pressure switch, located on the accumulator, and jump it with a piece of mechanics wire. This will force the compressor to stay running. Add freon until you have 30-35 psi.

Make sure you have the blower fan on high while doing it.

 

[jbaker]

Gotter fixed...shop put dye in last year....leaked out of r12 to 134 adapter....tightened up, over rode comp, and put a can in....now ice cold! Thanks for the help guys!

 

[#1HotRod]

Mine would run hot n cold, AC shop tech said freon was ok, needed new accumulator. After replaced accumulator (the're cheap but gotta evacuate system & replace freon) it kept cycling & AC tech said was low pressure switch. I got installed new switch from NAPA (easy fix, it only looses a smigon of freon replacing it) & now runs great & very cold. Counter jockeys don't know parts, so take original switch in as there are different types. Oh, while I was monkeying around I replaced the evaporator (also cheap but a tedious job getting it out of that damn plastic box, then resealing it back up. But, I highly suggest it because you get to see how corroded & narsty they get). It's now in the mid-high 90's here (but low humidity) & it works great. System was previously converted to the newer freon. Cheap & easy try is to put on a new pressure switch. Good luck.

 

[BADDGUY6]

Mine would run hot n cold, AC shop tech said freon was ok, needed new accumulator. After replaced accumulator (the're cheap but gotta evacuate system & replace freon) it kept cycling & AC tech said was low pressure switch. I got installed new switch from NAPA (easy fix, it only looses a smigon of freon replacing it) & now runs great & very cold. Counter jockeys don't know parts, so take original switch in as there are different types. Oh, while I was monkeying around I replaced the evaporator (also cheap but a tedious job getting it out of that damn plastic box, then resealing it back up. But, I highly suggest it because you get to see how corroded & narsty they get). It's now in the mid-high 90's here (but low humidity) & it works great. System was previously converted to the newer freon. Cheap & easy try is to put on a new pressure switch. Good luck.

Where did you get the new Evaporator from? Was it correct for a TR? I could not find a NEW Evaporator that was correct for a TR.

Thanks,
Guy

 

[#1HotRod]

Humm, I'll have to rummage through my receipt drawer (I'm at work now), don't remember if at regular outlet (Pep Boys or O'Reilly) or ordered it. I know I had to order the condenser & was afraid that the odd-shaped inlet/outlet tubes may be incorrect, but new ones matched fine. As for the Evap, do think got it at local parts store. It not specific for GN or TR, but thinking all those similar models would have same Evaps, dryers, etc. I got one for similar model, under $50. The original one is copper & narsty with corrosion & junk accumulates in the fins. Mine didn't leak in car, but can tell it had been seeping for years. New one is aluminum, wights a lot less, & fittings were the same (fit perfectly). Do recommend replace it, it's grunt work & have to tear things out of way, but along the way can clean & paint everything. It was 103 degrees here last week & AC worked great. Oh, taking off those damn rubber hoses from the Evap fittings not fun so I cut mine off. They are different sizes & one has a sharp bend...to replace that one I strongly recommend find pre-bent hose & cut it desired length (I tried to use straight hose & bend it, not worth the try).

 

[#1HotRod]

Where did you get the new Evaporator from? Was it correct for a TR? I could not find a NEW Evaporator that was correct for a TR.

Thanks,
Guy

Must have tossed receipt. I'm sure didn't order it & got it from Auto Zone or NAPA; I was surprised was in stock & inexpensive. Fit & works great. Sorry can't be more specific.