PeachParts Mercedes-Benz Forum - View Single Post - assitance requested with wiring a radio ina 1991 300

Ashman · #5 02-11-2001, 02:24 AM

Do you have a multimeter or test light?

I would start with one of those.

Test the wires for ground, test for constant power, and test for ignition power.

One of the wires is for the antenna. Use a process of elimination to check the wires.

To test for speakers you can use a battery to put power and ground through to hear the speakers make a pop. Only do this when you are sure you are using the speakers wires. you wouldn't want to send voltage through in car wiring to the fuse box or relays could hurt something.

Check for an illumination wire by testing a wire by turning the headlights on and off.

If you are in doubt about the speaker wires, you might just want to rewire the speakers. not a super fun task, dismantling interior, wiring cables, and all, but makes it easier to upgrade later to a better system with new speakers.

If you are looking for the color codes for the factory wires, do you have the manual for the factory stereo, it might have a wiring diagram, or the car's manual might have one.

If not you can check with the dealer or parts shop here for a wiring diagram.

In mercedes, generally brown is for ground I believe. if you plan on doing this yourself, get a test light or multimeter. It is an invaluable tool. The multimeter is better because it is more versatile. The test light is really only for simple circuit testing.

Alon