As it turns out, I have a talent for finding, or perhaps more accurately, creating mystery wires. Found one under the intake manifold when I did the injector valve o-rings. Found one in the dash when I replaced the radio. While I was sifting through the octopus farm behind the radio to find mystery wire #2 to put back in place, I found mystery wire #3.

The latest is brownish with a blue stripe. Female blade connector in a plastic fitting with an aluminum bracket. I found it behind the radio. Looking around back there with a mirror, I could not find a slot or a male connector to slide it onto.





Anyone have any idea what this is? Even better, any idea where it goes?

Thanks!
Tom

PS M impetus to get into the car to work was installation of the side mirror switch I was given for Christmas. That seemed to go well. I seem to knock more stuff loose in tighter confines, like the inside of the dash.

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2016 E350 4matic wagon
2010 ML350 Bluetec
1995 E300D Gone, but not forgotten.

it looks like a bulb socket maybe? Not sure. what it looks like to me

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hum.....
1987 300TD 311,000M Stolen. Presumed destroyed

Thanks!

I've been poring over my manual tonight looking for "/bl" on the wiring diagram. There are a handful of that correspond to illumination on the AC vents and the headlamp switch, etc. Maybe I unhooked the ashtray light, or some such. I'll test that the next time I am in the car in the dark.

I appreciate the suggestion.

Tom

__________________
2016 E350 4matic wagon
2010 ML350 Bluetec
1995 E300D Gone, but not forgotten.

I think it is a ground wire for the factory radio. Don't worry about it.

__________________
Not MBZ nor A/C trained professional but a die-hard DIY and green engineer. Use the info at your own peril. Picked up 2 Infractions because of disagreements. NOW reversed.

W124 Keyless remote, PM for details. http://www.peachparts.com/shopforum/mercedes-used-parts-sale-wanted/334620-fs-w124-chasis-keyless-remote-%2450-shipped.html

1 X 2006 CDI
1 x 87 300SDL
1 x 87 300D
1 x 87 300TDT wagon
1 x 83 300D
1 x 84 190D ( 5 sp ) - All R134 converted + keyless entry.

Hmmmm. I'll look at the back of the original radio to see if I can find a mate.

Thanks for the thought!
Tom

__________________
2016 E350 4matic wagon
2010 ML350 Bluetec
1995 E300D Gone, but not forgotten.

yup...the original radio will have something to plug that into.

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85 190E 2.3(SOLD)
86 230E (-->300D) sold
87 300D (-->300TD) sold
68 250S w/ a 615 and manual tranny (RIP)
87 300TD (SOLD)
95 S280 "The KRAKEN" (Turbo 2.9 602 transplant) traded
86 190E 2.3... current project

aren`t ground wires brown? he said it is brownish with blue stripe.

Charlie

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there were three HP ratings on the OM616...

1) Not much power
2) Even less power
3) Not nearly enough power!! 240D w/auto

Anyone that thinks a 240D is slow drives too fast.

80 240D Naturally Exasperated, 4-Spd 388k DD 150mph spedo 3:58 Diff

We are advised to NOT judge ALL Muslims by the actions of a few lunatics, but we are encouraged to judge ALL gun owners by the actions of a few lunatics. Funny how that works

That wire plugged into the casing of the OEM radio. The metal clip gave it away. It will be touching the casing to ground the radio, it may be an electrical static thing as there is a ground already.

__________________
Not MBZ nor A/C trained professional but a die-hard DIY and green engineer. Use the info at your own peril. Picked up 2 Infractions because of disagreements. NOW reversed.

W124 Keyless remote, PM for details. http://www.peachparts.com/shopforum/mercedes-used-parts-sale-wanted/334620-fs-w124-chasis-keyless-remote-%2450-shipped.html

1 X 2006 CDI
1 x 87 300SDL
1 x 87 300D
1 x 87 300TDT wagon
1 x 83 300D
1 x 84 190D ( 5 sp ) - All R134 converted + keyless entry.

I believe that it is the security wire to the original radio. If connected/disconnected in the incorrect sequence with the battery connected, it will render the radio inoperable. If the radio is removed with the alarm sounding, it will render the radio inoperable.

For an aftermarket radio this wire is not used.

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Gone to the dark side

- Jeff

Is there a fatcory alarm on the car?? Sounds like the alarm connector to the radio

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Keep us posted especially if your problem is solved
Present cars:
My car: E-class 420CDI, 2008, W211, V8, 180 000km

Wife's one: C-class 220CDI Sport Coupé, Euro, 2002, W203. 345 000km

Son's one: GLK class 220CDI, 2009, W204

Sold E class 260E, W124, 1988 beloved car sold after 489 000 kilometres of reliable services (engine M103, clutch and 5 speed manual gear box all original).

E-class, W210 320CDI, 2000[/B], 225 000km, Sold

Yup, that's for the alarm. The shape of the plug makes it pull off the back of the radio when you remove it from the dashboard, which locks the radio.

-J

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1991 350SDL. 230,000 miles (new motor @ 150,000). Blown head gasket

Tesla Model 3. 205,000 miles. Been to 48 states!
Past: A fleet of VW TDIs.... including a V10,a Dieselgate Passat, and 2 ECOdiesels.
2014 Cadillac ELR
2013 Fiat 500E.

Thanks for all the info, guys!

Regards,
Tom

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2016 E350 4matic wagon
2010 ML350 Bluetec
1995 E300D Gone, but not forgotten.

Just to tie up the loose end, I pulled out the old radio. There is a male blade connector at the bottom on the back of the radio. The goofy aluminum bracket looks like it would end up right along the bottom of the radio if the spare wire were connected in that spot.

Thanks for all the helpful replies!

Tom

__________________
2016 E350 4matic wagon
2010 ML350 Bluetec
1995 E300D Gone, but not forgotten.