Servo Cruise Control - Wiring Continuity Testing
Continuity testing is typically performed if you want to make sure that there are no breaks in a wire. At our cars' age its always a possibility.
To begin this testing all you will need is a multi-meter, a length of wire, and a helper! This test is done with both the actuator and the amplifier disconnected and the car off!
Step 1) Set Multi-Meter to Resistance mode or Continuity mode if so equipped.
Resistance Measurement Mode - Low Cost multi-meter (harbor freight/amazon)
Resistance mode range on this meter is in the red box. Set it to the 2000 or 200 range.
Step 2) Use the table below to connect your probes. You will need a length of wire to extend one of the probes to be able to reach the connector.
wiring for mercedes cruise control, 14-pin sytem
wiring for mercedes/porsche 10-pin vacuum cruise systems.
Simply connect one probe to the pin indicated in the amplifier connector. Then connect the other probe to the associated pin on the actuator connector.
The meter will read out a value if you have continuity between the two points. It it does not read anything and simply says "1____" try adjusting the range to a higher setting. If you still see no value then there is a break in the wire somewhere.