W123 - Best place to tap in constant 12V for radio clock
 

Good evening,

I need 12v constant for the the clock in my new aftermarket radio. only a few mA's.

anybody have an elegant way of doing this to the fuse block
(or anywhere else for that matter) ? I looked up there and it doesn't look easy to tap into the fuse that has the other constant 12V stuff on it like the clock.

maybe i'm missing the secret technique of getting to the back of the fuse block...

dd

Use the supply to the cigarette lighter........much easier than the fusebox.

I tapped into the wires from the rear dome light switch.

Cigarette lighter is switched on a 123.

how about tapping into the... clock? it has a constant 12v supply, and it's not very far away from the radio. it's labeled on the back of the instrument cluster, and it's a standard 1/4" spade connector.

Mine is tapped from the +12 volts from the hazard light. I think it was a Red/black wire, and a P.O from a long time ago kindly left me a splice covered in electrical tape there.

The OE radio connection already has constant 12V for a clock. Why can't you use the old connection?

:dark:

Guess you can't smoke with the engine not running............:o

There has to be a constant 12 line to the original radio. We need somebody with the electrical ts manual to figure out what color it is.

Bad for your health... :D

You can't even honk the horn in my 126 without turning it on. However, the radio will work anytime...

I agree with the above, the stock radio has a constant 12V source. Time to get the test light and figure out which one it is.

Hmm, Ill test it out to see if there is one and report back...

On mine, both +ACC and +BATT were both red wires with no markings differentiating them. I ended up running a brand new line from the battery to the radio anyway, though. Throug the wiring harness thing at the firewall (there are about 6 small channels made for this purpose with caps on them, remove cap, run wire through, and I put a dab of silicone sealant on it to seal it up again)

There's a wire right there...
 

I just did this on mine and it was fairly easy as all the wires were already there although unconnected to anything. Here's the rundown:

1. Blue wire with spade connection - goes to antenna (power)
2. Grey wire with male plug - goes to antenna
3. Socket that gives 12v keyed - Brown is [-], Black/yellow stripe is [+]
4. Black socket gives constant 12v - Grey/Purple strips is [-], Red is[+]

On your aftermarket radio, they will have many warnings about connecting the right wire to the right (switched or unswitched) sources. I would heed these warnings. I found everything worked exactly as expected with the above connections made. I believe the white, keyed socket is connected to the cigarette lighter (I wouldn't know as mine was disconnected) You don't need to make any kind of new wiring as its all inside. Wiring the speakers is another story...

Hope this helps!