A/C Help After 5.3 Swap
 

Hi Everyone. Swapped a 5.3 from a 2002 Tahoe into our 97 2 door Tahoe. We have been driving the thing all over the place because it is so much fun to drive now.

https://photos.smugmug.com/97-Tahoe-...8_004357-L.jpg


But it's getting pretty warm out now so I really need to figure out the A/C.

I made the harness by combining the 97 and 02 together to just use the computer from the 02.

The compressor is a Sanden 508.

https://photos.smugmug.com/97-Tahoe-...%20-%204-L.jpg

I have the A/C Low Pressure Switch at the Drier and an A/C High Pressure Switch installed in the high pressure line between the condenser and compressor.


I tried this wiring diagram...

https://photos.smugmug.com/97-Tahoe-...Van%20AC-L.jpg


This wiring diagram...

https://photos.smugmug.com/97-Tahoe-...AC%20Fix-L.jpg


And this wiring diagram...

https://photos.smugmug.com/97-Tahoe-...%20HVAC-X3.jpg

I do not have an A/C High Pressure Recirculation Switch installed. Honestly I did not even know that was a thing until the other day. I guess the factory compressor has a spot for that switch. The Sanden compressor has no provisions for switches.

Any help with this would be greatly appreciated. I have to go to Arizona next week. Yikes.

Re: A/C Help After 5.3 Swap
 

Well according to this list of A/C switches from the GMT Service Manual, I have the switch names wrong...

https://photos.smugmug.com/97-Tahoe-...h%20List-L.jpg

The A/C Low Pressure Switch in in the high pressure line? I thought it was on the accumulator.

The switch on the accumulator is actually the A/C Compressor Cycling Switch.

So it looks like I don't actually have a high pressure switch in my system.

Dang this stuff can get frustrating.

Re: A/C Help After 5.3 Swap
 

Can you even get the compressor to come on by jumping 30 and 87 on the AC relay socket?

Re: A/C Help After 5.3 Swap
 

Even better than that, if I jump the A/B terminals on the two switches I have, the compressor will come on with the switch located on the HVAC Control Panel. I have to jump both of them with a small wire. Only jumping one or the other will not make the compressor operate.

It blows super cold, but I don't want to run the A/C without the safety of the switches to keep me from hurting the compressor.

Re: A/C Help After 5.3 Swap
 

So what exactly (according to the drawing) do you have connected?

Re: A/C Help After 5.3 Swap
 

I have to show you what i did to my 99 2dr 2wd I used ICT billet bracket that used stock vortec compressor and stock hoses i took everything out of a 2005 gmc sierra was 4.8 5spd 2wd i used a 04 rainier aluminum 5.3 rest of the 05 complete harness steering column cluster all stock is in the 99 dash allmost done with it looks factory in there even the 05 electric fans fit in it making a 99 2wd 2dr limited tahoe ground efx and all wheels ect fog light bumper I will get some pics I have 7 2dr tahoes here

One 96 lifted 14 inches on 38s solid axle swap 5 speed 4x4

Re: A/C Help After 5.3 Swap
 

I have tried all 3 of the different setups with no luck.

The problem I am having at this point is terminology and what component is actually where.

The only thing I think I am 100% sure about is the wire coming from C2-43 on the computer that goes to the A/C compressor clutch relay in the fuse box that then goes to the plug at the compressor.

The light green wire from the HVAC control module is supposed to go to one side of the Low Pressure Cut-Out Switch, but now I'm not even sure where that is.

C2-11 A/C Cycling Switch
C2-17 A/C Request Signal
C2-33 A/C Recirculation
C2-43 A/C Compressor Clutch Relay Control
C2-55 A/C Low Pressure Cut-Out Switch

I thought for sure someone in the San Diego area would be able to help me out, but none of them want to deal with wiring.

Re: A/C Help After 5.3 Swap
 

Seven 2d Tahoes? Wow. It's awesome seeing solid axle swapped trucks. It's too bad GM went the IFS route on their 4x4s.

Any info you could offer on the A/C stuff would be awesome. Pics of the wires coming out of the different switches, or whatever.

Would love to see pictures of your projects. Feel free to hijack my thread. LOL Always fun to see other's projects.