factory AC with Vortec swap

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81waggy
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Joined: Wed Mar 09, 2016 7:30 am

factory AC with Vortec swap

Postby 81waggy » Mon Jun 18, 2018 6:36 am

Quick question. If your keeping the factory AC but dropped in a vortec (in my case, the 5.7) how do you control the compressor? Do you need to install an on/off switch? swap to specific compressor?

Thanks.
81 Wagoneer with a TBI 350 Vortec...More Power!

RamJetFSJ
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Location: Carpinteria, CA

Re: factory AC with Vortec swap

Postby RamJetFSJ » Mon Jun 18, 2018 7:43 am

Are you trying to use the compressor that came with the donor motor? If so do you know what model it is?
80 Wag in 73 attire, Ram Jet 350 power

RamJetFSJ
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Re: factory AC with Vortec swap

Postby RamJetFSJ » Mon Jun 18, 2018 7:47 am

The A/c system controls the compressor, it’s just a 1 wire connection. It doesn’t need to know what motor it’s bolted to. But if the new compressor has different fittings, or is 134a, you’ll need to update the old system to match.
80 Wag in 73 attire, Ram Jet 350 power

SJTD
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Re: factory AC with Vortec swap

Postby SJTD » Mon Jun 18, 2018 8:25 am

How was it controlled before?

Mixing new and old AC technology might not work well.
Sic friatur crustulum

'84 GW with Nissan SD33T, early Chev NV4500, 300, narrowed Ford reverse 44, narrowed Ford 60, SOA/reversed shackle in fornt, lowered mount/flipped shackle in rear.

81waggy
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Re: factory AC with Vortec swap

Postby 81waggy » Mon Jun 18, 2018 9:04 am

I was hoping to use the compressor from the donor just because its there. Part number SAE-J639. its a Delphi running 134a. It came out of a 2000 Escalade and has a 2 wire connector (1 black 1 green).

I knew I was going to need new hoses made to connect everything. I just don't know how it operates to know if I need a switch to kick it on or not. Seems like most of the aftermarket AC kits either have dedicated button to turn it on, or a specific control just for it.
81 Wagoneer with a TBI 350 Vortec...More Power!

RamJetFSJ
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Location: Carpinteria, CA

Re: factory AC with Vortec swap

Postby RamJetFSJ » Mon Jun 18, 2018 12:05 pm

The Binary switch in the A/C system controls the compressor (it does not necessarily come on as soon as you push the A/C button in the cab. it kicks the compressor on at certain system pressures, and has a high pressure safety).

On the FSJ A/C system, since its just a separate A/C system with no heater, it tells the compressor to come on (as long as the pressures are correct) as soon as you turn the fan on at all. I dont think you can run the fan w/o the A/C going. You would use the heater for that.
80 Wag in 73 attire, Ram Jet 350 power

SJTD
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Re: factory AC with Vortec swap

Postby SJTD » Mon Jun 18, 2018 12:07 pm

I'd do a little research on the donor system.

Since at least '98 VW has used a variable displacement pump with a fancy expansion valve. Both hoses go through it. It doesn't normally cycle the clutch on the pump. Some newer versions never turn the compressor off.

Idunno what GM has been doing.

A lot of guys have used that motor so the info should be out there. I just don't recall seeing it addressed.
Sic friatur crustulum

'84 GW with Nissan SD33T, early Chev NV4500, 300, narrowed Ford reverse 44, narrowed Ford 60, SOA/reversed shackle in fornt, lowered mount/flipped shackle in rear.

81waggy
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Re: factory AC with Vortec swap

Postby 81waggy » Mon Jun 18, 2018 4:25 pm

SJTD wrote:I'd do a little research on the donor system.

Since at least '98 VW has used a variable displacement pump with a fancy expansion valve. Both hoses go through it. It doesn't normally cycle the clutch on the pump. Some newer versions never turn the compressor off.

Idunno what GM has been doing.

A lot of guys have used that motor so the info should be out there. I just don't recall seeing it addressed.


Haven't been able to really find anything either. Seems that most guys just swap it out with a vintage air or something like that. I've thought about it but I really don't want to abandon my factory heat controls. Most topics are more concerned with relocating the compressor than how it functions.

Even though I'm going with a completely custom look, I'm trying to stay as factory looking as possible with factory heat and ac controls, retrosound bluetooth radio, and a custom center console similar to the super wagoneer complete with a twin stick shifter look, (which is really an A/T floor shifter and a np241 shifter).
81 Wagoneer with a TBI 350 Vortec...More Power!

myjeeps3
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Joined: Thu Aug 06, 2015 2:29 pm
Location: Tucson,Arizona

Re: factory AC with Vortec swap

Postby myjeeps3 » Tue Jun 19, 2018 3:27 pm

I have a 1979 j20 with a 5.3 swap. To control the donor compressor just use the AC power wire from the under hood fuse box that controlled the original compressor. Power to green wire and black wire to ground. Works great!

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sonoraed
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Re: factory AC with Vortec swap

Postby sonoraed » Wed Jun 20, 2018 5:59 am

if the engine came from a 2000 gm truck it's probably a LM7 5.3 LS type Vortec engine if this is the case the compressor is a 10S20F Delphi the SAE is not a part number just the standards the comp is made too,the wire to activate the clutch should come thru the firewall with the hoses,power for this wire comes from the ignition switched side of switch thru the blower switch to the thermostat and onto ac compressor clutch (assuming pre 86 evap) would recommend removing evaporator case (have to anyway to replace hoses) for cleaning (usually lots of debris in core) check wiring to make sure it's in good shape and replace expansion valve, flush condenser and replace drier, oem style drier doesn't have a place for trinary switch (high/low pressure cut out) so would replace with aftermarket drier, there is more detail but this with give a general idea how to do the properly

csuengr
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Re: factory AC with Vortec swap

Postby csuengr » Thu Jun 21, 2018 2:51 pm

I have a 1997 Ford compressor with my 1977 Cherokee stock AC system. After finding all hose adapters and getting new hoses made (which of course leak), my system runs fine, when it's not leaking or housing cracking. I also don't have a pressure switch, so my compressor comes on anytime the switch is on (one wire).

KEEP DEBRIS OUT OF YOUR HOSES!!! Your expansion valve, and knuckles, will thank you.
1977 Cherokee S, Ford 5.0, 5 speed, BW 1356, 33 x 10.50 BFG's. My DD and only vehicle.


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