Red and Green Wire.

[tel76]

When i removed the wiring loom located in the engine bay from the rust bucket (1968 280sl LHD) prior to carrying out all the welding that was required,i found that where the wire for the CSD exits the loom there is also a Red and Green wire that exits in the same position,this wire is connected to a white wire that goes back through the bulkhead and was the supply for the radio.
I have just refitted this wiring loom and would like to know if this is the correct power supply for the radio, if not what should this wire provide power for?
As matter of interest i found that the modifications to the lighting system ,presumable on importation from Europe to the US (hazard warning and fender repeater lights,it was originally a Belgium car)the power had been taken from the supply going to the inspection plug on the bulkhead,a 1/2inch section had been exposed and the wire for the hazards/repeaters had been wrapped around this supply (no soldering or anything) then around this makeshift joint was wrapped a small amount of masking tape.
If anyone has a vehicle that has had any modifications carried out to it should check the installation and that any additional equipment goes through a fused supply.

[Larry & Norma]

Check to see if the red/green wire has no power when ignition is off but has power when in ignition position 1, if so then
this is correct for the radio.

[tel76]

I would have expected the radio supply to come from a source inside the car,it does seem strange to pick up the power from this location when you could pick up the supply from the fuse box inside the vehicle.
Can someone have a look at there vehicle and inform me if they have the same set up?

[mbzse]

When i removed the wiring loom located in the engine bay.../...
I have just refitted this wiring loom and would like to know if this is the correct power supply for the radio, if not what should this wire provide power for?

These wires are intended for an electric (motorized up/down) antenna, and also for constant 12V feed to the radio unit. The factory mounting instructions tell that such an antenna should be fittted on the right fender, just in front of the windshield of a W113 (instructions show exact spot where the drilling should be done).
All W113 had these wires in the wiring loom, but folded and hidden. You have to slit the sheath to extract the wires.
/Hans in Sweden

.

[Larry & Norma]

On my 1971 280SL there are two wires in the loom where you say. One has power in ignition pos 1, for the radio. The other has permanent power
for the antenna or memory for modern radios.
They are traceable back thru' the fuse block i think.

[tel76]

Hello Gnu,
If you have two wires exiting in this location,where does your CSD wire exit?
Hello Hans,
Thank you for your response on this matter it does make sense to supply the aerial from this location,although it would have made more sense to supply the aerial from inside the car, it does beg the question of where does the supply for the radio come from?

[Larry & Norma]

Hi Eric,
The wiring for the CSD and brake fluid level switch etc also come out of this loom an inch or two further on.
I agree it is a strange place to have the radio wires but I guess radios were a bit of an after thought in the sixties.
In most cases you would have had to wired it all yourself. Mercedes inccluded an ignition switched wire and later a
motorised antenna supply - quality cars
This is exactly where mine is wired and I have also added an extra fuse box to protect the radio and antenna.
Just force the wires through one of the grommets on the bulkhead.
Hope this helps
Larry

[tel76]

Hello Larry,
From your response it would appear that your car is a RHD this one is a LHD.
I wonder if anyone knows where the red and green wire originates and does it pass through a fuse?

[Larry & Norma]

Hi Eric,
Yes i do have a RHD.
Do you have a Haynes manual, if so look at wiring diagram on page 181, it shows item 50 as optional radio supply.
If you trace it back through the ignition switch it is powered in position 1 and then goes directly to the battery
and is not fused. You should therefore fuse this output if you use it.
It makes sense to use ignition pos 1 as you can then use the radio without having the engine running.
If you have a powered antenna then this needs a permanent live so that it can still power down after the ignition has been switched off.
Hope this helps
Larry

[tel76]

Thank you Larry, i will wire the radio as per your info: when i get that far down the long road.

[Larry & Norma]

Ok Eric, I cannot claim all the credit here as Naj originally advised me as to the whereabouts of these wires
Do we get to see any pics of your car yet?

[Naj ✝︎]

Hello Larry,
From your response it would appear that your car is a RHD this one is a LHD.
I wonder if anyone knows where the red and green wire originates and does it pass through a fuse?

Red/Green wire on right inner fender/wing on LHD car connected to twin fuse box.

Picture could be better !!

[tel76]

Hello Naj,
Have you got a photograph showing the full location,i have not got the fuse box,you indicate that it is a dual fuse box, does one fuse supply the radio and the other the aerial?

[Naj ✝︎]

Hi, Eric,

This one should do?

The other box is an after market solid state voltage reg.

naj