Changing the head unit

[JaceyBoy]

Do I need to buy an adapter to be able to change the merc head unit for an Alpine one?

[JaceyBoy]

Weird, I have iso connections yet they seem to be differently wired even though the iso connectors fit?, Help!

[gchild]

i've not needed adapters for a w202 and w210 i've swapped units in.

[JaceyBoy]

Hmmmmm, and that was fitting an alpine unit?

[gchild]

no. pioneer and kenwood. The headunit side should be a standard wire arrangement, its usually the car side that has a different arrangement therefore requiring an adapter.

What problem are you experiencing? h/u not powering up or remembering station presets or something?

[JaceyBoy]

No power at all, and when comparing connections the live and earth are in different places on the iso connectors

[gchild]

may be it has been messed with. Have you checked the obvious things like fuses on the car and h/u side?

unless for your particular car an adapter is required...but theres nothing listed that i can find for your car

http://www.caraudiodirect.co.uk/fitting-adaptors-mercedes-c-292_306.html

[gbjeppm]

Check if there is a switched 12v feed to the ISO connector, the alpine unit might need one, if I remember correctly as standard there is not one, there is only a permanent feed. If you need a switched 12v you can tap into the cigar lighter.

I had to to do this for the Parrot I installed, and it might be the same issue.

[JaceyBoy]

Its bloody odd, the car doesnt look as if the old stereo has ever been out:confused:

It just seems the wires within the block are in diff places so I would assume I need a harness, but as you say there is nothing listed:confused:

[KillerHERTZ]

Ive always needed adaptor cables for my Alpine units. around £12-£15 from any car audio place.

If its for an old Alpine unit for a W202, I have a spare cable

[JaceyBoy]

Its a fairly new unit, 2006 I think, spoke to Alpine UK and they said something about a switched power:confused:

[gbjeppm]

Its a fairly new unit, 2006 I think, spoke to Alpine UK and they said something about a switched power:confused:

See my previous post No 8.

[JaceyBoy]

Yep it seems that what I need to do, so is it an easy case of tapping into the positive on the cigerette lighter and connecting to the alpine?

[gbjeppm]

Yes should be, take out the ashtray, there will be 2 wires going into the cigar lighter, brown is the earth and the other one (2 colours one of which is pink) is the 12v switch. (I think, please test with appropriate tester to make sure):)

Tap the pink one, and run it round the back to the Alpine unit, not sure which pin is the switchable feed on the Alpine unit, but there should be a wiring diagram on the Alpine site for your radio.

Hope this helps.

[gchild]

odd that there isn't already switched live feed in the iso on the car side...otherwise how would the h/u switch itself off/on with the ignition?

let us know how you get on

[gbjeppm]

odd that there isn't already switched live feed in the iso on the car side...otherwise how would the h/u switch itself off/on with the ignition?

let us know how you get on

I believe that the CAN sends a wake up message, which is why there is no switched feed, perhaps somebody more knowledgable than me can confirm.

I can confirm though that mine has no switched feed as standard.

[merc man]

You need to take the live feed from the passenger side floor, its behind the plastic trunking i believe, and run that to the head unit, test for a switched live or you could just take a live feed and fuse it before the headunit, but the headunits wiring loom should have 2 connectors one for constant live and one for switched live and you put the live in the app. connector and it will work as it should, ie switch live when ignition is on regards less if its constant or switched live.
hope that helps

[merc man]

I believe that the CAN sends a wake up message, which is why there is no switched feed, perhaps somebody more knowledgable than me can confirm.

I can confirm though that mine has no switched feed as standard.

yep you are correct!

[JaceyBoy]

Thanks to gbjeppm its all sorted, I had to take a live switched feed from the cigerette lighter, easy and all done and working now:bannana:

Cheers