Hi Guys;

I need to call on your wiring experience. I tried posting on other sites with no response, I'm afraid.

Getting towards the bottom of my list of things to sort on my 1992 500E.

Earlier, I did a quick install of a new Pioneer Premier DEH-P790BT tuner, cd, head unit so that I could have tunes while I worked on other stuff.

I left the orange/white for the deck's lighting until I had more time. Currently it lights up fine, but it is a bit dazzling on dark roads. The installation manual instructions only say "connect to lighting switch terminal".

OK, so which part of the switch to connect the wire to?
I haven't hooked up this sophisticated a unit before.

Can I expect current coming from the 'hot' terminal when the lights are on, to signal to the headunit to dim the illumination?

I don't want to blow the deck. Anybody familiar with this?

I know this is not a big deal, but I would like to lessen the time I spend contorted under the dash and the risk of silly, but expensive pyrotechnics.
I am sure many of you have dealt with this.

Any help would be appreciated, thanks.

 

Modern MBs have the signal at the CAN-bus but since your car would not have it (and likely the new HU does not have the input), you could feed the illumination control line e.g. from the hot wire of the cigarette lighter bulb (I assume it is controlled on your car too, when you adjust the IC illumination).

 

Thanks Diesel;

That certainly makes sense. I am not sure that the cigaret lighter or ashtray are lit, but I have not checked it yet as I do not smoke. However, some instrument lighting must be easier to access than the headlight switch.



Much appreciated.

 

I always hook the wire up to the headlight switch, get a test light and find the wire that turns the interior dimmer lights up and down. That way you can adjust the level of illumination. Go direct to the light switch, Try not to connect to other parts of the car,( cig lighter) if that ever has a problem one time it might mess up the radio. Good Luck!

 

Thanks "Justin"

 

My car does not have the controlled illumination wire at the main switch but older cars may have that. It should be fine using that, but it would be equal to tapping the same wire from one end or the other, or somewhere in the middle if instead hooked to a hot wire of a controlled bulb.

I suggest the car owner to get sufficiently familiar with the wiring and then decide himself the best way, or if there is any difference. Some wiring diagrams could help too, not sure if the car would be mostly at least covered here:
http://www.autolib.diakom.ru/CAR/Mercedes-Benz/