There are professional recovery/recycling/recharging machines that evacuate the system with a vacuum pump and separate the water, oil and refrigerant. After making sure the AC system holds vacuum (no leaks), you can recharge it with the proper weight/volume of refrigerant with one of these. If your system has lost all its Freon, you can just use a vacuum pump. Ones that draw enough vacuum are usually expensive (at least $150-200 for a decent refurb'd one). I bought an almost new R12 recovery/recycler system off eBay for less than a vacuum pump. I wouldn't recommend it unless you are a comitted do-it-yourselfer. It's more complicated than using a pump on a dead system, but it does allow me to deal with a system that is partially charged, but I'm still fussing with it. Unless you are a do-it-yourself nut, just take it to a shop and have them recover the coolant and check for leaks in the process and give you a proper charge.

 

So .... anyway .... I connected 12v to the compressor and guess what ... ICE COLD AC. Now all I have to do is trace the hot wire to the front. Then I'll have my ac back.

 

probably your relay in the a/c head controller in the dash. there is a thing on how to do it somewhere online with the diagram and using a radio shack relay.

 

My 84S AT USA came with Freeze-12 in it. It cools fine. I've looked on the web and it seems like a viable option to R134 and has R12 compatiblity advantages. You can buy it on ebay for $8/can. Anyone else have any experience with it?

 

Louie Ott has had pretty smokin' results

 

Jack thanks Brother, I'll look.

 

Check the easy stuff first... Fuse, Freeze Switch(easy to check, hard to change), low pressure switch(Don't run compressor if this shows open circuit), Temp switch, Connectors, wiring. THEN check the relay in the head unit. You can check everything else without disassembly(except for the rain shield). If the low pressure switch checks out as "open" then the whole problem may be due to a slight loss of freon. A set of gauges will be reqired to find out whether it's that or a bad switch. The temp switch can be replaced without opening the system if it's like the early cars.

If the relay in the head unit checks out OK you may want to protect it by using it only to activate an added power relay instead of actually powering the clutch, which it seems is a bit much for it.

 

Heinrich,

Louie did not have a problem with Freeze 12. He had problems with Envirocare actually. Feeze 12 is a 134a slurry derivative and very non flamable. Envirocare is a a Butane and Propane mix that can catch fire.

Good luck.

 

I used freeze 12 in a conversion I did a few years ago. It worked well for the two seasons I kept the car. The only complaint I had was that it seemed to lug down the compressor and engine at idle.

 

Heinrich
Sounds like you got off easy this time....unless the control head turns up faulty!

I belive the correct weight for an S4 or newer without rear air is around 900-950G, with rear air is 1100-1200g...the manuals have the exact numbers. I had 2.6lbs (1180g)or R12 added to my completely empty system (with rear air) earlier this year....after the heater valve fix (on a 90 degree day) I am getting air temps (main center vent) in the 26-30 degree range...I would guess the rear air is even colder!
Brian

 

Dudes, I'll dig in soon ... who knew it was all so complicated

 

Don't blame that little relay before checking out the low pressure switch and the freeze switch.

 

Heinrich,

Send me an email to techAT928gt.com (change AT to @) and I will send you a paper on the HVAC system.