transplanting rear AC in a '91 1500 burb without rear ac.

[Stowburb]

 Hey Guys,
Getting ready to transplant the rear AC from my '88 r-20 burb into my '91 1500 burb. i have already removed the system( less the blower wiring) from my '88. and going to install it in my '91 1500 burb. the donor burb had a 454 with a tailgate,The '91 is a small block with barn doors, so i know a few parts will be differnt.....the compressor hoses, And the trim that covers the hoses that run down into the floor.but i robbed those parts from the junkyard for 20 bucks.
 Just wondering if anyone has done this? looks like it will be a pretty simple swap. I think the biggest thing will be the blower wiring. i think i will use and "aftermarket" blower switch because it is round  so all i will have to do is drill a hole somewhere on the dash.
 Anyway, if anyone has a few tips, let me know.
Thanks,
      Chris

[Captkaos]

No tips but I would like to see your progress if you post some pics.

[Stowburb]

Cool, Chris I'll try to get some pics, i just finished removing all the wiring from my "donor" truck.. and it looks like it is all independent from the wiring of the front ac system, the only deference that i have found is the blower resistor for the rear fan is mounted in the front ac box on the side closest  to the valve cover and i'm sure there is no hole punched in the firewall, so i will have to cut those in.
 Dont think its gonna be bad,tho.I saved the headliner from the donor truck also, so i will not have to cut up my "perfect" headliner, i'll just have to recover the AC headliner.
 i'll get lots of pics.
Chris

[Stowburb]

Hey guys, i'm getting ready to tear into my truck and install a factory rear AC unit into her.....got all the parts and have a planed course of action, so i thought i'd drop a few "before" pics on ya and i'll take lots of em all through the install.....

[Stowburb]

Hey guys, just finished installing my rear ac in my burb! looks great and works like it came in the truck!
 I will post pics of the completed job soon, As i'm heading out of town for a week. So i will see how well it does with 4 people in her for an 8 hr. drive. Wish me luck.

[VileZambonie]

Good luck. Glad to hear it worked out!

[Captkaos]

Sweet, glad it worked out.  awaiting for some pics.

[GhettoBurb]

Rear air makes all the difference in the world with these old burbs. I took the variable orifice out and put a fixed orifice in and it seems to work better for me. I was running 414B refrigerant at the time and have since switched back to R12. I noticed no temp difference between the two. I have not tried to convert to 134A yet, but once I need to recharge the a.c. again I will give it a try and see the temp difference. I hope that is a while off though as I put the R12 in last summer and it was expensive to buy the stuff. Now if I only had rear heat. I am thinking of giving that one a try eventually using the parts from a newer burn or other vehicle with rear heat.

[Stowburb]

I converted it to 134a freon when i recharged it after adding the rear unit. It kicks booty!  Had to run both blowers on Low, it would get so cold! Traveled 8 hrs. 1 way and 10 hrs. home and it did great with no issues at all! not bad for a 400 dollar truck with 270,000 miles on her.
Rule of thumb is you use 80% r134a of whatever the required amount of r-12 is. I think my burb with front and rear air takes 3 lbs. of r-12.
Well, when i get slowed down alittle i'll get some pics of the finished project and post them here so you guys tell me how it looks.

[GhettoBurb]

I am afraid I will probably have to try R134a next time around. I don't have access to R12 any more. I have already converted my cr over to R134a, guess the truck will be next once the time comes.