I have an '88 560SL.
The car intermittently stalls when driving with the A/C on. When this happens the check engine light goes on and a code 7 is stored in the computer.

According the the Mercedes manual, a Code 7 indicates a problem with the Ignition Contro Unit or the Idle control unit.

I've read a number of articles on trouble-shooting this and one article linked the A/C to the Idle Control Unit. The article found that with a malfunctioning OVP relay the A/C drew down the current to the idle controller thus causing the stalling problem.

Does anyone know the location of the OVP so I can check/replace it. The manual indicated that it is next to the passenger foot well. I looked but only saw a relay by the fuses and it wasn't the OVP relay.

If this isn't the solution, does anyone know what else could be causing the stalling or further troubleshooting steps to take?

Thanks,

Patrick