300SL odd air con problem

[Jubag]

Hello, I have a very nice 1990 R129 300SL. I just had it regassed today and all went well, holds gas etc. Only problem is the compressor only works if you put a 12v feed onto the blue and green stripped wire on the compressor itself. The only other time the compressor will run is if you have left the car off for some time and you start it up, for about two seconds the clutch will engage and then trip out.

I think I'm being a bit hopeful, but does anyone have a wiring diagram for a 300SL, or maybe able to point me in the right direction?

Is there a relay for the air con? If so where is the blessed thing?

I have checked the compressor fuse, that's fine.

[Jubag]

It's odd because I've checked for power to the pressure switch and there is nothing there, all so the switch has continuity so I'm guessing that the circuit is closed because there is gas in the system.

Are there any wiring diagrams anywhere?

[Jubag]

jimdollar said:

Try this site http://www.sf.nexedge.com.my/129/etm/webetm/129/st... or join the benzworld.org forum, acres of info on there, hth, Jim.

Absolutely spot on Sir! Thanks for that info. 👍🏻

[Jubag]

Hello! Thanks for the advice, in the end I just ended up rewiring the main circuit with a standard relay and a hidden switch. Works a treat!