108 Wiring Harness Question - PeachParts Mercedes-Benz Forum

Tom Drew · #1 08-09-2004, 10:16 AM

I've just finished the long and hard job of removing, refurbishing, and replacing the heater box on my '72 280 SE. I've been very careful to take photos, keep notes, bag and label fasteners, and mark wire harness connections. I'm at the point now where I've re-installed the heater box, evaporator box, and the heater controls with all cables hooked up, and I'm ready to install the large A/C duct with the vents and controls. In checking all my harness plugs before I installed the A/C duct, I've got a four connector female harness plug that is not marked, and I can't figure out where it goes.

This plug terminates under the glove box area. It is five inches or so shorter than the six connector female plug that connects to the A/C air duct at its right hand end. Is it possible that this is an unused connector in the 108 but maybe used in the 109 models? This is the only thing I can think of - maybe I didn't mark it upon disassembly because it wasn't connected to anything, but still tied in to the harness.

If anyone could shed light on this I'd be grateful. I don't want to button everything up only to have to take it apart again to make this connection. Thanks to all in advance.

Tom Drew

300SDog · #2 08-11-2004, 04:32 PM

Tom, was your 108 ever equipped with power antenna mounted on the right front fender??

If not, then MB might have anticipated this option and included an electrical hook-up to accomodate this feature.

yeldogt · #3 08-11-2004, 09:07 PM

My 109 does have a different setup then my older 108 -- the 109 has this thing that is set into the AC evap box -- kind of an extra fan control.

The 108 just had a single wire going out to the a/c compressor and one to the fan on the right kick panel. Also the power feed from the fuse box on the right side of the engine bay came through the same harness. The system is so simple that it should be easy to just trace the controls.

The a/c was by itself -- I do not remember any other things (like the power ant) in with it.

Give a little more info - maybe it will spark my memory!

Tom Drew · #4 08-12-2004, 10:01 AM

Thanks guys, both good suggestions. I had not thought of the power antenna. Since my car has a manual antenna, this could be it. Although it seems the antenna feed would not require a 4 connector plug. Has anyone replaced their power antenna recently and remembers the location and type of power feed?

Interesting suggestion about the evaporator box connection. I know for sure that my 108 evaporator box has no electrical connections. I've just had it out of the car to test and clean the coil and replace the expansion valve. Anyone know any more about this 109 evaporator box electrical connection?

Thanks again for taking the time to help.

KyGuy · #5 08-12-2004, 12:52 PM

The power 'tenna doesn't require a 4-prong feed.

Tomguy · #6 08-12-2004, 06:21 PM

There is a 4-connector plug right by the heater levers on the box, iirc, that this plugs into, it's the heater fan power. At least on mine, that sounds what you're describing.

Tom Drew · #7 08-14-2004, 12:12 AM

Thanks Tomguy, but the 4 connector plug supplying the heater box fan power is connected and I'm sure it's the right harness plug. The four connector plug I'm trying to ID it tied into the harness under the glove box area.

Now that the weekend's here I'll try to trace the wiring backwards and see where it originates from.

cth350 · #8 08-14-2004, 11:06 AM

The service manual has the wire harness layout by color code.
First thing to do is get the color patterns of the 2-4 wires in the harness.

-CTH