No power at ignition wire

[ps2cho 10+ year member]

I got everything so far lookin good in my 1987 Mercedes 260E.

...but I can't seem to get any power from the ignition wire for some reason. The +12V constant reads 12v...but (ignition on obviously) the +12V switching wire reads nothing.

I have replaced the fuse in the fusebox and still nothing.

Would I be able to bridge it with the constant +12V? If so would it drain the battery if I made sure to turn off the radio before I left the car? (for a temporary solution until I can get an electrical diagram for somewhere to attach to)

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[fasfocus00 5,000+ posts]

did you turn the key and test the ignition source?

 

[ps2cho 10+ year member]

did you turn the key and test the ignition source?

Yes I did.

I got everything so far lookin good in my 1987 Mercedes 260E.
...but I can't seem to get any power from the ignition wire for some reason. The +12V constant reads 12v...but (ignition on obviously) the +12V switching wire reads nothing.

I have replaced the fuse in the fusebox and still nothing.

Would I be able to bridge it with the constant +12V? If so would it drain the battery if I made sure to turn off the radio before I left the car? (for a temporary solution until I can get an electrical diagram for somewhere to attach to)

 

[x1le 10+ year member]

Check your cigarette lighter and see if that's switched. Otherwise run it to an accessory in the ignition harness.

I personally wouldn't ever run it to a constant, but yes, it will work.

 

[Beerdrnkr 5,000+ posts]

I have the same problem in my car Suzuki right now. I just sent a power wire to the battery and manually turned off the HU for a temporary solution. I'm thinking there's another fuse somewhere between the harness and fuse box.

 

[ps2cho 10+ year member]

Check your cigarette lighter and see if that's switched. Otherwise run it to an accessory in the ignition harness.
I personally wouldn't ever run it to a constant, but yes, it will work.

Good idea about cigarette lighter. That will work!

I'm relatively new to electronics. I had bestbuy install my headunit in my other car because it was free...but I'm reasonably handy so I figured I'd give it a go myself this time.

That should do the trick. I'll report back if it doesn't.

Thanks!

 

[SicAudio 5,000+ posts]

those old german cars usually have a weird relay setup IIRC so try something else that has switched power.

 

[ps2cho 10+ year member]

those old german cars usually have a weird relay setup IIRC so try something else that has switched power.

Yep that worked so its powered up now.

I'm really struggling figuring out the wires for the speakers...this sucks //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif

Spent the last hour searching M-B forums and can't find anything on what color wires that go into the fader are for the speakers.

 

[oldschool4me 10+ year member]

they dont make a wire harness kit for that?

 

[stocker08 10+ year member]

I had this problem with my car also. I just ran a new wire from an accessory fuse in the fuse box. Fairly easy. Haven't had any problems since.

 

[ps2cho 10+ year member]

they dont make a wire harness kit for that?

They do, but it only covers the Ignition, constant, ground and power-ant.....all of which can be cut and done for free....sure its easier....but I'd rather save $35. I'll never take out this HU so its not like im making it hotswappable.

 

[SicAudio 5,000+ posts]

and the way the electrical is setup on them is thru odd relay setups. constant power actually shuts off lol so much for constant power! have you seen the funky fuses the old european cars use? weird shit man. 22 yrs as a tech I never saw such a mess in my life as they are lolz.

 

[ps2cho 10+ year member]

and the way the electrical is setup on them is thru odd relay setups. constant power actually shuts off lol so much for constant power! have you seen the funky fuses the old european cars use? weird shit man. 22 yrs as a tech I never saw such a mess in my life as they are lolz.

You mean these ? //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

 

[Beerdrnkr 5,000+ posts]

So what's the cause of this?

 

[ps2cho 10+ year member]

No idea...

I got a question though -- My Pioneer headunit (DEH-2100I) won't save any of my settings....Is that normal? If I change the equalizer and turn off the unit -- then back on it won't save it.

Could it be possible I have the constant + ignition wires the wrong way around? Or would that not make sense?