A/C. Where do I start? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Jonathan70 · 03-11-2014, 02:02 AM

Hey guys,

I recently bought a 1970 swb with factory a/c. The a/c compresser isn't hooked up to the pulleys son obviously something went wrong sometime ago. I want to restore ac in my truck. The question is, Where do I start? It seems that all the components are there.

Thanks!

Jonathan

chuckmc8 · 03-11-2014, 05:20 AM

Welcome to the board Jonathan. Do you have a way to make a set of pics and post them to your thread? Those really help folks here see exactly what you have :-)

MARKDTN · 03-11-2014, 07:21 AM

Most likely all that is wrong is the compressor is locked up. Check and see if you can turn it. If it needs replacing, you can stay stock or upgrade to a Sanden style. You can remain with R12 or convert to R134 refrigerant. If it were me, I would stay stock and stay R12. You will probably have to take it to a shop and have them properly evacuate the system. Then replace the compressor and dryer and maybe the main hose. Evacuate it and charge it and hopefully be blowing cold air. You might check to see if you are getting 12V to the compressor to be sure the electrical side is good. Also make sure you have all the fan speeds. Repair those issues as needed. That is the high-level view.

Jonathan70 · 03-11-2014, 11:08 PM

Thanks Mark!

The compressor does turn freely. I'll check electrical and evacuate.

Thanks

mrein3 · 03-12-2014, 11:57 AM

I did a write up a few years ago. Since you have everything, skip down to post number 8 in this link for a procedure to follow to get everything up and running:
http://67-72chevytrucks.com/vboard/s...d.php?t=478564

Regarding keeping it R12 verses converting it to R134a, its a horse a piece. The cab on a truck is small so the less efficient R134a works ok. I converted my truck to run R134a. I keep my Chevelles - which have identical systems - running R12 because they have a lot more space to cool. First attempts at factory R134a used condensers they had with the R12 systems. These condensers didn't work as well with the R134a. More modern systems have a more efficienlty designed condenser which will cool your cab down better - but it isn't a drop in. If you're not afraid of fabbing connections from your stock system to a condenser out of a junk yard, do it and you'll freeze yourself out of that cab with R134a.

BMERDOC · 03-12-2014, 12:06 PM

I can't argue with mrein3's take on recommisioning the A/C system. If you try to skimp you'll just end up in heart ache when you need to do it over again. The only thing I would add is to wire an electric fan so that its on when you turn the A/C on. Don't wire it so that it cycles with the compressor. You system will be blowing snowballs!

03-11-2014, 02:02 AM	#1
Jonathan70 Registered User Join Date: Mar 2014 Location: San Diego, ca Posts: 2	A/C. Where do I start? Hey guys, I recently bought a 1970 swb with factory a/c. The a/c compresser isn't hooked up to the pulleys son obviously something went wrong sometime ago. I want to restore ac in my truck. The question is, Where do I start? It seems that all the components are there. Thanks! Jonathan

03-11-2014, 05:20 AM	#2
chuckmc8 It's alsways something..... Join Date: Nov 2008 Location: Douglasville GA Posts: 1,171	Re: A/C. Where do I start? Welcome to the board Jonathan. Do you have a way to make a set of pics and post them to your thread? Those really help folks here see exactly what you have :-) __________________ 1968 RS Camaro 'Vert Matching number 327 and M21 Muncie 1968 C10 Black with red interior and orig paint. 5.3 / 4l60e,3:73 POSI 17" Torq Thrusts 1968 CST 514 Red with black interior. Buddy Buckets, Factory A/C, PS, PB- 20" AR custom shop TT, 5.3 and 4l60e

03-11-2014, 07:21 AM	#3
MARKDTN Registered User Join Date: Jan 2011 Location: Chattanooga, TN Posts: 2,167	Re: A/C. Where do I start? Most likely all that is wrong is the compressor is locked up. Check and see if you can turn it. If it needs replacing, you can stay stock or upgrade to a Sanden style. You can remain with R12 or convert to R134 refrigerant. If it were me, I would stay stock and stay R12. You will probably have to take it to a shop and have them properly evacuate the system. Then replace the compressor and dryer and maybe the main hose. Evacuate it and charge it and hopefully be blowing cold air. You might check to see if you are getting 12V to the compressor to be sure the electrical side is good. Also make sure you have all the fan speeds. Repair those issues as needed. That is the high-level view. __________________ '83 K20-TPI '73 C10 '79 C10-ex-diesel(SOLD) '07 Tahoe(Son driving) '14 Suburban-DD '71 C10-current project

03-11-2014, 11:08 PM	#4
Jonathan70 Registered User Join Date: Mar 2014 Location: San Diego, ca Posts: 2	Re: A/C. Where do I start? Thanks Mark! The compressor does turn freely. I'll check electrical and evacuate. Thanks

03-12-2014, 11:57 AM	#5
mrein3 Registered User Join Date: Feb 2000 Location: Center City, MN, USA Posts: 3,254	Re: A/C. Where do I start? I did a write up a few years ago. Since you have everything, skip down to post number 8 in this link for a procedure to follow to get everything up and running: http://67-72chevytrucks.com/vboard/s...d.php?t=478564 Regarding keeping it R12 verses converting it to R134a, its a horse a piece. The cab on a truck is small so the less efficient R134a works ok. I converted my truck to run R134a. I keep my Chevelles - which have identical systems - running R12 because they have a lot more space to cool. First attempts at factory R134a used condensers they had with the R12 systems. These condensers didn't work as well with the R134a. More modern systems have a more efficienlty designed condenser which will cool your cab down better - but it isn't a drop in. If you're not afraid of fabbing connections from your stock system to a condenser out of a junk yard, do it and you'll freeze yourself out of that cab with R134a. __________________ '70 cab, '71 chassis, 383, TH350, NP205. '71 Malibu convertible '72 Malibu hard top Center City, MN

03-12-2014, 12:06 PM	#6
BMERDOC Registered User Join Date: Jun 2011 Location: Richmond,Va Posts: 2,934	Re: A/C. Where do I start? I can't argue with mrein3's take on recommisioning the A/C system. If you try to skimp you'll just end up in heart ache when you need to do it over again. The only thing I would add is to wire an electric fan so that its on when you turn the A/C on. Don't wire it so that it cycles with the compressor. You system will be blowing snowballs! __________________ Nick Carter 1967 C10 Short bed Fleetside Project Cheap Thrills! 2WD C10 Modern/Performance Alignments Easiest Alignment Ever!



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