96 S10 Blazer AC
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TECH Apprentice
Joined: Aug 2005
Posts: 347
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From: Dover Arkansas
96 S10 Blazer AC Well, finally got all my hoses in and evacuated system. Everything held, no leaks. So I jumped the compressor clutch after pumping 12 oz of R134 in and getting the LP switch to close. I didn't have a big enough fan to cool it while charging the R134 so pressure went up quick and was taking forever to charge. Tommorrow gonna put the garden hose on it and charge another can in. I think it will take total of 24 oz.Still have to figure out how to wire up the thing. I'm thinking just wiring LP switch, HP switch in line from AC switch to a relay to power the compressor clutch. Then run line to another relay to turn the fans on when AC is on. Put some diodes in to keep fans from energizing AC clutch when not on. Think this will work. Thanks. Any other suggestions appriciated.
Thread Starter
TECH Apprentice
Joined: Aug 2005
Posts: 347
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From: Dover Arkansas
By the way, this is on a 2005 5.3 with all truck accessories in 96 S10 Blazer using underhood fuse box and pcm from 2005 Suburban. If anyones figured out how to get the truck pcm, (which requires a serial data signal from HVAC module to control ac) to work, I sure would like to know. Thanks
It should work fine with just the LP switch. I know BlackX runs his through the low pressure cycling switch on the drier only. As far as the fans...yes it could work the same way just make sure you put the diodes in. Its easily made as a stand alone system and from what you wrote...sounds like it will work. Mine since it is Fbody PCM...i have the LS1 HP switch in tandem with the stock LP cycling switch hooked up into the PCM so I get the fans and idle bump already.
The way you are wanting to do it is pretty much the way it is set up from the factory on the 96 minus the pcm controlling it. On the passenger side the a/c request is the lt green in the round plug from the control head. Just loop the a/c request through the lp sw on the drier and then to one side of the relay coil pin 85. Ground the other side pin 86, on pin 30 of the relay supply constant 12 and run pin 87 to the a/c clutch coil and it will work fine.
Oh yeah...i meant I already have mine wired up....haha sorry for the confusion. Mine is set up to where the LP switch cycles since I am using the Sanden 508...and I have the High Pressure switch on the hardline that feeds the PCM so I get the idle bump and all that good stuff. Mine works great just it does it like I am inside the truck turning the A/C on and off as it cycles. But the way you said is how it would be if I didnt wire through the PCM
Thread Starter
TECH Apprentice
Joined: Aug 2005
Posts: 347
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From: Dover Arkansas
Thanks for all the replies. Put another 12 oz of r134 in today. Used a garden hose to cool the condensor. Just jumpered the clutch so I could charge it up, so my fans weren't kicken on. I'll work on that tommorrow. I might try leaving the high pressure switch wired to the pcm and see what it does.
