560sl Fan Blower/AC Question

[orbit398]

I have an '88 560SL. Wondering what is going on with the Blower/AC system. System is fully charge, has new compressor, dryer, high pressure and fan switch. Cools great when the system is on. Issue is that it shuts off and comes back on randomly. When is shuts off, both the AC compressor clutch and blower turn off. Then back on and cools great, then back off.....

I have take the AC controller apart and re-soldered suspect spots, did the same on the blower control unit. Pin #6 was discolored, re-soldered that spot on the circuit board.

Reassembled it all and no change. If I turn key on, blower will run forever. It only acts up when the engine is running. Any ideas? Could the Temperature Regulator box (aluminum covered one on fire wall) be the issue?

thanks

[Diseasel300]

Does the R107 still have the 2-piece HVAC control in '88? I'd expect something that's causing both compressor and fan to misbehave to be in the pushbutton unit or a wiring fault. If you still have the original aluminum fuse feeding the pushbutton unit, replace it with a brass or copper one, the aluminum ones can develop tiny fractures that can cause all sorts of irritating problems as they age.