Author Topic: A/C problem  (Read 10418 times)

Offline 1979C20

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Re: A/C problem
« Reply #15 on: September 14, 2012, 10:01:05 PM »
Cool, I crossed those part numbers at my work and found that we stock both of them. Couldnt look it up by application though. About 11 bucks each so itll probably be 6 or 7 each my cost. Im pretty sure its still r12 because the fittings are original and I cant see any stickers or tags indicating it wad converted. Thanks guys, ill try the A/C selector switch first and fix the blend door. If that doesnt work, ill try the blower switch. If all else fails ill just run a toggle and have my refrigerant topped off.
1979 SCLB C20 Q-jet 350 SM465 14b F.F. 4.10 G80
1989 GMC Suburban V2500 TBI350 TH400 4in lift 35's 14b SF

Online bd

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Re: A/C problem
« Reply #16 on: September 14, 2012, 10:38:14 PM »
Kyle, inspect the switches and connectors for signs of melting/burning.  It's a common problem on this style of switch.  If melting/burning has occurred, replace that switch and its connector (heat anneals the electrical terminals and they lose tension).  You may not need to replace both switches.  From what you've posted, I'd look first at the blower switch.  Good luck with your repair.
Rich
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Offline 1979C20

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Re: A/C problem
« Reply #17 on: September 15, 2012, 02:44:13 AM »
Thanks for all of the help bd. Ill pop my dash bezel off when I get off work tomorrow and see what I can come up with.
1979 SCLB C20 Q-jet 350 SM465 14b F.F. 4.10 G80
1989 GMC Suburban V2500 TBI350 TH400 4in lift 35's 14b SF

Offline 78 Chevyrado

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Re: A/C problem
« Reply #18 on: September 15, 2012, 05:00:31 PM »
Show a pic of the fittings to put ac into the system.  that will tell you whether its 12 or 134.
Kenny

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Offline 1979C20

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Re: A/C problem
« Reply #19 on: September 15, 2012, 08:18:56 PM »
Its r12 fittings.
1979 SCLB C20 Q-jet 350 SM465 14b F.F. 4.10 G80
1989 GMC Suburban V2500 TBI350 TH400 4in lift 35's 14b SF

Offline 1979C20

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Re: A/C problem
« Reply #20 on: September 16, 2012, 11:25:01 PM »
I got my A/C working! I pulled my cd player out and reached up behind the A/C switches and found that the A/C selector was partially unplugged. I plugged it in the rest of the way and it all works now. But, the rear A/C is ice cold and the front blows warm. I made sure the blend door was set to cold too. Any ideas?
1979 SCLB C20 Q-jet 350 SM465 14b F.F. 4.10 G80
1989 GMC Suburban V2500 TBI350 TH400 4in lift 35's 14b SF

Online bd

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Re: A/C problem
« Reply #21 on: September 17, 2012, 12:44:39 AM »
Hooray on the switches!  If only every repair were that simple.

Have you checked your refrigerant charge yet?
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline 1979C20

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Re: A/C problem
« Reply #22 on: September 17, 2012, 01:36:32 AM »
I havent checked the charge yet. But once it has been running for like 5 mins with the ac on the clutch stops cycling and stays on. One question, do I HAVE to remove the shrader valve from the low side fitting to put the r134a fitting on and have them be functional? One of the installers who comes in my work all the time said he will do a tune up on my r12 but he can only do it with the r134a fittings.
1979 SCLB C20 Q-jet 350 SM465 14b F.F. 4.10 G80
1989 GMC Suburban V2500 TBI350 TH400 4in lift 35's 14b SF

Offline Edahall

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Re: A/C problem
« Reply #23 on: September 17, 2012, 07:35:26 AM »
But, the rear A/C is ice cold and the front blows warm. I made sure the blend door was set to cold too. Any ideas?

A blocked front orifice tube (or filter) would cause these symptoms.  However, if it's blocked, you need to figure out what's causing to get blocked.
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