A/C Starter Relay (Code 4)

[79300SDPhil]

I was wondering if anyone could tell me where to find my A/C Starter relay on my 1979 300SD W116. On the electrical schematic it shows the coil of it connected to terminal 50 of the ignition switch via Violet/White wire.

I have my dashboard off and have found the Violet/White wire. It's a much heavier gauge wire then what it says on the schematic.

There was an aftermarket relay from a very old looking alarm system. I removed that whole mess. I believe the relay was simply interrupting the Violet/White wire between the ignition switch and Starter Lockout switch?


Please see attached photo of schematic.


Phil

[cooljjay]

You have the evil servo system. Besides the amplifier behind the glove box, the only other two relays associated with the system are under the hood on the drivers fender well...on the w123 that is but should be in the same location..

[79300SDPhil]

Thanks cooljjay. Would you happen to have a picture of where it's at?

I think I may have partially figured it out. I have a 1979, but I think my ignition is wired as a 1980. I was just looking at the wiring diagram for an 80 online. It seems to match what I have in my car more than a 79.

It still shows a A/C Start relay but the power is picked up at the 105 junction (I believe this is the big power junction under the car's battery).

On the '79 wiring diagram the power to the relay comes straight from the ignition switch.

In 1979 the A/C Start relay would control both the compressor clutch and in the starter solenoid.

It looks like for 1980 they tried to reduce the chances of a no start situation by ONLY allowing the A/C Start relay to control the engagement of the A/C compressor clutch.

I still need to figure out where this relay is at.


Phil