Hello All,

1993 Bonneville SLE, 101k miles, r12 to r134 conversion performed by professional shop in 1998. For years I have tolerated semi warm vent temperatures but since I drive the car so infrequently, it never really bothered me. Put this one away in the winter (have a 96 Buick as year round daily driver, also 3.8L)

Buick has been down and out, so the Bonny has been put into service. Has been hot as hell here (Buffalo NY believe it or not) so the semi warm ac put me into action.

Have never touched the system in the 13 years I have owned the car, and not sure what condition the ac system was in, so I did the following:

-Had Pep Boys evac and leak test the system. No leaks.

-Ran my 2.5cfm vacuum pump on the system for 45 minutes just to be sure all moisture was pulled from system as a precaution.

-Did my calculations of r134 vs. r12 for the refill, took three 12 oz cans of r134 which resulted in 33oz of refrigerant and 3 oz of oil. Purged yellow fill hose of air with refrigerant to remove air before filling system. Compressor started up about third of the way through the first can. Compressor runs quietly and continuously. High and low side gauges are in proper ranges.

-Lowest vent temp is about 55 degrees, doors open, system on max cool ambient temp about 80. Basically the same performance I was getting before the evac and recharge. I dont think it is a blend door issue because defrost and all other settings seem to function fine (i.e. air direction changes as I change the directional settings). Obviously I am looking for somewhere around 38-42 degrees at the center vent. Pipe running from the accumulator to the compressor ice cold and lots of condensation dripping.

Your thoughts and suggestions are most welcome.

Thanks,

Dennis

Based on what you already addressed, it sounds like a blend door issue. Start by going through this thread: https://www.gmforum.com/mechanical-134/default-redirect-cooled-air-late-model-gm-cars-96-2000-a-279092/

You may actually want to check out this thread:

https://www.gmforum.com/1992-1999-91/ecc-blinking-air-mix-actuator-fixed-installation-pics-274213/

The issue does sound like it could be the blend door, but the topic posted is for the air diverter, not the air temp. The actuator is electronic, and likes to break.

Thanks guys for the advice. I started to look at a couple of other things and noticed that my cowl vents and outside of my condensor looked pretty gunked up. Soooo....I took the garden hose and blasted the cowl vents free of all the leaf and bird crap remains that collected in there. I also blasted the front of my condensor with engine degreaser, let it sit for a half an hour, and then hit that with the hose making sure I didn't bend any fins, etc. It pretty much removed a substantial amount of grease bugs and road crap from the front of that as well. Once I did that, my vent temp dropped to 39 degrees at idle! Looks like problem solved, just needed to be attentive to some obvious maintenance that got overlooked. Happy camper now......

I love easy fixes.

Very cool. I was thinking something along those lines too, but I discounted it because I was thinking it would cause the high side pressure to spike. Guess I was wrong!