Woogi

well i have a 92 hb that when i bought it, it had a blown ls in it, we swaped to a b20 now the a/c (r-12) doesnt blow cold. We didnt unhook the lines (cuz r12 is hella expensive). I KNOW it blew cold before the swap, and im pretty sure it did afterwards, but now the compressor doesnt come on. I tested two pins on the ECU (p75 obd1) and they where both good, (forget what pins but 1 was in "A" block and one was in "b"). Anywho i read that if the unit is low on r12 the compressor wont kick on. So my question is, do you guys have any diag tips for me. I heard you could jump the relay some how, and other stuff like that, but i couldnt get a pinout for the relay. Also, the compressor is fine, there is just no power getting to it. (how much should i see 12v)? thanks

EG2Driver

Check all the wiring again. Also check if you damaged the condenser. Crusty white stuff means its been punctured.

Woogi

any place i can get a good idea as to what wire has what voltage, and when

EG2Driver

I know nothing about AC, but common sense tells me that the power wire going to the compressor when the compressor cycles would be a good time to check for voltage.

sauceja

Basically all you need to convert to r134a ? is a new drier (cylinder coke can thing that has a site tube on it by the washer resevoir) and the two little hootus things for the fillers.

Evacuate all R12 change your drier and convert to R134a. There is a conversion chart to find out how much to use and don't be a jackass and do it yourself with the cans. Those things blow **** up if you get to much pressure.

The R12 sits lower than 134 and it won't mix or mess anything up.

Ask your honda service manager what I am talking about. I did it to my 91 accord wagon with all oem parts. With employee discount it was around 120.00 that was just the parts not counting a/c refrigerent.
I had to change a piece out though as per the service bulletin.

But its possible.

My .02

Woogi

yeah but i want to make sure i can get the compressor to turn on, if i find out that is the issue (im low on r12) then i prob will just swap it over.

sauceja

Yep there is a pressure switch somewhere on the small line I think? You need to get live wire from battery and check that. Your compressor will either come on or not.

But before you go trying this get a manual or something that explains the a/c a little better because it has been around 15 months since I last messed with this.

The conversion I know is good but this test I am 50/50 so I am just being honest.