240 90 240 A/C to 93 System Full Blown Swap

Hi All,

I'm starting this thread as a placeholder to help others who are looking to do the same of converting -90 240 systems to the 93 set up to get R134a the right way. I plan to do a full write up. There's a 93 in my local junkyard so I figure why not just go for it.

My knowledge however is a bit limited on the subject matter.

I know from the 93 I will need virtually everything right? Including:

• Compressor
• Lines
• Condensor
• Evaporator
• HVAC box
• Dash Snowflake Switch?
• Brackets
• PS Pump? Is it different from 90 to 93?
• Wiring, lots of wiring. How much is plug and play and how much is 93 specific?

Any guidance here would be greatly appreciated. I'm looking at my Bentley manual for the physical items to pull and the wiring diagrams online to see what might or might not match up.

Cheers

There have been several threads in the last year that document the conversion completely; many have gone this road successfully.

My best advice on 134a conversion: weigh the freon when you install! Proper amount of oil in all locations, and don't over/underfill the system!

There is not a ton of wiring, switch, relay, 2 sensors and a fan. And the 5 blower fan wires. You will have to get a ton of wiring (everything else )out of the way. The firwall is practically barewhen the HVAC box comes out. if the 93 is rusty , the tubing connections to the condensor may be corroded solid.
I have 4 1993 245s.
Getting the AC out of the last 1993 was a bitch, despite a warm, well equipped garage, n which I dismantled the ENTIRE car.

Finding new condesers and compressors was not easy, those 93 parts are one year only 240 parts.
My advice:
The Rubber mountings of the puller fan are crappy and expensive. Go with an aftermarket fan mounted to the condenser.
depending on the rustynss, consider a custom condenser custom hoses and hard lines plumbed with modern, common fittings(cost is similar in the end vs finding good quality fitted parts) Next time I pgrade a 240, or update one of my 1993s, I'm going to use the 1993 HVAC box, but find the best modern compressor that fits in the bracket, dealing with finding a 1993 240 only parts sucks. Good arguments for a NEW, not remanufactured compressor also tip me towards this approach

Overall, this job becomes most sensible when the interior is all out, and the engine is out too. But isn't everything easier that way lol

Also pointless to convert to 93 without sealing the condenser to the opening like factory did with seals and foam to force maximum air through it, along with using both little and big belly pans. A must do.

On an auto car that might ever get a manual, swap in a 3 pedal box, better to have a flopppy third pedal that to open patient twice.

Overall, it's a worthwhile project in an appropriate receipient, but def do it during a major overhaul, not just by itself. I can answer specific Qs if you ask.

Good luck with the harvest from the 93, it's gonna be a bear in the JY, get the fancy 93 only heated power mirror system while you are there.