antenna trigger wire - PeachParts Mercedes-Benz Forum

waba · #1 12-17-2012, 08:53 AM

Hi all,

there was no headunit in the E320, so bought a new one. the foure leads that went into the becker-connector went into the corresponding ISO leads, and all working smooth (continuous power, ignition, light-switch & ground).

speakers: all four hooked up, fading & balancing as they should (with both original fader and fading from the headunit).

last part: the blue wire for antenna up/down: none to be found. only cables left are two wires each in a separate harness.

1. Black and ends in a connector with two leads, of which the other one is not connected

2. brown/blue striped. ending in a cable shoe with a weird spring like outer part.

did see the diagram in this post

W124 Help Identify the power antenna wire...

does antenna control go to two black wires on the top right part of the scheme?

pls help

thx

JW

jay_bob · #2 12-17-2012, 10:19 PM

Typically on the Becker the antenna control is a flat blade connector. It looks like a little flat tab recessed in a pocket in the rear of the radio. It is about 1/4 inch or 6 mm wide.

The connector on your harness should resemble something like the photo under "FASTON Electrical Quick Connects" at this link: Terminals & Splices - TE

The antenna control wire is typically blue in the vehicle harness. It often has black sheathing over it so at first glance it appears that it is a black wire.

Early 124s did not have the rear amplifier so they had a single pilot wire to the antenna. On later 124s with the rear amp the wire splits in two, one goes to the amp control and the other to the antenna. Check your trunk, you might well have one of the amplifiers there if your car is 1990 or newer.

Your new stereo should have a blue wire. It is just a switched +12 V output that is limited to a few hundred mA. This is meant for raising the antenna or switching remote amplifiers. You should be able to connect the blue wire from your new stereo to the vehicle blue wire to raise and lower the antenna.

The springy thingy goes to the anti theft alarm. It is sensing ground so it would be prudent to insulate it and store it away behind the dash so that it does not contact ground. It attached to the back of the Becker radio in such a way that if the radio was pulled it would fall off and trigger the alarm.

There should also be a 5-pin flat connector. This will have one or more wires on it. These are also grounds that work with the alarm and can be disregarded. If there is a green/yellow wire on pin 3, that is the vehicle speed signal. This should be insulated so that it does not bring down the rest of the VSS network for the other devices that use it (cruise control, ACC, engine management, OAT display).

Also I recommend lifting up the console wood, tracing out the wiring to the fader, and separating out the 4 sets of speaker wires and directly connecting them to the 4 channel outputs on your head unit. The fader cannot handle the power of modern car stereos. Others on the board have taken the fader apart and worked a USB or mini-jack into the faceplate to serve as the connector for their aux-input.

waba · #3 12-25-2012, 04:46 AM

thanks JayBob for the reply.

I think I got most right. Still the antenna is not moving, so methinks some deeper surgery is needed. Hoping to avoid it, but may have to remove the center rollo box and other stuff covering the wiring harness, and then dig in for a real blue wire. There is nothing that i can fish from behind where the beceker used to be.

The springy-thingy was around the flat bladed connector like the one in the photo. However the wire therein did not do the trick when attached to the blue cable that comes from the radio. Did check that indeed that one gives +12V when the radio is on, and it does go off when the radio is switched off.

alternatively, i can try to go for the antenna from the trunk. Rig a 12V pulse to the antennna relay, and see if that pops it up. perhaps it is broken there...

thx

JW