Condensor Fan A/C Mod

[tucsonjwt]

I added an auxiliary pusher fan to the 134a converted A/C on my 83 C20. It made a big difference in cooling at idle - not R12 quality but close.

I used a relay which had 12 ga. color coded wire hard wired in - so no need for extra spade connectors. I got a $35 condensor fan from a 1998 Chevy Metro at the pick and pull, since that was the only one I could find small enough to fit the opening (about 12".) I used about $40 in additional supplies, so about $75 total.

I mounted the fan with rubber grommets squished between the mounting tabs on the fan and the surface of the core support (like a rubber washer.) I was able to through bolt the one tab on the core support vertical, but used self-piercing screws on the two tabs on the opposite side.

I grounded the fan to the core support with the wiring and eyelet salvaged from the Metro. I used my secondary start battery on the driver's side for constant power (30 amp fuse), and used the fan clutch power wire for the "signal circuit" (5 amp fuse.) One wire went from the relay to power the fan, another wire from the relay went to ground at a screw inside the core support near the battery.

I used this graphic (page 3, "Single A/C Fan Only) as a guide:

http://www.davebarton.com/pdf/coolingfandiagrams.pdf

[killa496]

What parts did u use to change over to r134? My 77 needs a compressor and lines. Hell just about everything. Thats a great idea using that pusher fan. have to try that will i get my parts together

[tucsonjwt]

I had the A/C changed over about 10 years ago. I think the current thinking is that you don't need to change much, but I will let others cover that topic. I am still using the old A6 compressor that came with the truck when I bought it used.

[gchemist]

Sweet!! I may do that to mine!! The small fan is cheap enough to junk when it fails!! I can put a bypass for long distance driving!! Can you post a picture of the entire front? I want to see how it will fit with my external oil cooler on the passengerside.

[tucsonjwt]

I have a stock oil cooler on the driver's side.

[gchemist]

Shine a light on it!! It's all black!!

[tucsonjwt]

No access to camera now. Try enlarging the pic - it worked for me.

[1slo_camaro]

love it man, im about to convert over to 134 when i get home and not sure if im gonna need a fan in there or not. love this tho!

[rambler]

great job,, subscribing for easy search later when I add AC to my rig

[SCOTI]

I did a similar deal utilizing the OE GM set-up on my dually.

The placement of things originally was not condusive to efficient cooling. I relocated the fan to the center of the condensor/radiator, relocated the oil cooler as far over as possible on the drivers side so there would still be good air-flow (but less restriction to the cond/radiator), & then added a similar trans cooler on the pass side (also as far out of the way as possible while still allowing good air flow).

About ready to start the motor & will see if the a/c temps are improved over last time used.

[tucsonjwt]

I am sure that dual condensor fans to cover the entire condensor would be best, but I did not want to mess with the original oil cooler location. My initial excitement with cool air at idle is a little less with the temps back up around 106 and heading to 116 later this week - but still much cooler than it was and I don't have to rev the engine at idle to get some cool air out of the ducts.

[y5mgisi]

I like the idea!