Alpine Head Unit Won't Power On - SOLVED :D

[Mauler]

I've checked this site quite thoroughly and I've seen very similar questions asked but not often concluded (so sorry if I've missed a solution somewhere)



My CDA-9853R unit is dead when connected to my G-Limited loom - not even a whir from the inside when the ignition wakes up! It was fine in my Probe. All the wires in the Alpine loom match up to the colours in the existing loom just like the JVC head unit that I took out but the JVC works no probs.

It's (the JVC) back in the car and powered for the moment but now I get no sound and my clock's reset! I'll check the footwell fusebox tonight as the 'dome' fuse I checked this morning under the bonnet is fine...

I've no idea what gives - all the connections are good, the red & yellow +12v & the ground all match up and look fine. The blue antenna & blue/white amp power have been scotchlocked together by someone in the past so that when the JVC powers on it's remote antenna signal activates both the MR2's amp and leccy aerial. That's the only thing that seems to not match up. That and the orange illuminations wire which doesn't connect to anything.

To summarise:

The JVC unit was a bit pikey but worked fine via the MR2 amp.
I remove the JVC unit.
I connect the 'power' half of the MR2 loom into the 'power' half of my Alpine loom. It matches colour for colour.
I connect the Alpine loom & 4 phonos to my CDA-9853R.
I hit the ignition and I get a loud POP from the speakers but no power from the Alpine, no internal whir or a flicker on the panel.
Connections are all fine.
Look confused.
Take Alpine + Loom back indoors.
Put JVC unit back in.
JVC powers on and appears to run fine but there's no sound at all.
Search this site for info.
Notice that like in another post my clock has reset.
Post here for help.

Very frustrating. I didn't have a multimeter to hand but surely if one headunit with the same connections & connector works then power is getting to the loom/head fine?

'elp!

[johnnymr2]

check the rear plates of both units, most have a diagram of the pins denoting what they should be connected to. make sure that they are both the same. then go out, stop being tight and buy a multimeter, it will save you money and ball ache in the end. the load 'pop' sounds like your amp is getting some kinda dc input, make sure that the amp hasnt blown the fuse or worse still thrown its hand in

[Mauler]

check the rear plates of both units, most have a diagram of the pins denoting what they should be connected to. make sure that they are both the same. then go out, stop being tight and buy a multimeter, it will save you money and ball ache in the end. the load 'pop' sounds like your amp is getting some kinda dc input, make sure that the amp hasnt blown the fuse or worse still thrown its hand in

Yup yup the connections all match up on both units. I've just put the Alpine back in my other car and it worked straight off the bat. Very strange. The amp started working when I put the JVC back in too so at least I have some tunes.

But...can someone who knows about ICE tell me something? Do head units earth through their aerial connection?? Because the JVC head is dead until I connect the car's aerial into it and then it whirs into life. I'm wondering if the JVC is earthing thru the aerial connection because the loom's earth is crap?

Meh

[johnnymr2]

well the outer of the coax for the aerial is grounded to stop pick up, and if you had a multimeter you could test the continuity of the ground through your loom

[Mauler]

well the outer of the coax for the aerial is grounded to stop pick up, and if you had a multimeter you could test the continuity of the ground through your loom

I'll tap my Dad for his tomorrow - we shall see

[pccalloutservice]

i had problems with my alpine as well, get a pic up of loom if possible coming out of your headunit.
i had to cut and change afew wires, but finally got it working.
if isee the pics i will check against mine and let you know wat to change

[SteveTMR2]

Well i do believe what will solve ur problem would be switching the red and yellow wires, as on some models this is the other way around...
these are switched and perm lives

[Mauler]

Well i do believe what will solve ur problem would be switching the red and yellow wires, as on some models this is the other way around...
these are switched and perm lives

Ah, see I tried that already - no joy.



I have it sorted though. The Alpine loom has a black earth, this connects onto the adapter's black wire which connects to the MR2's brown earth wire. This apparently was connected to...nothing. No earth was the problem! The JVC worked because it's aerial connector is part of the casing and the unit was earthing through the aerial but the Alpine's aerial connector is on a wire like a dongle so the casing couldn't earth through it.

One bolt in the back of the head unit, a wire with a hoop connector at each end and one bolt in a metal part of the dash next to the glovebox did the trick...like hell am I gonna trace that iny earth wire without a Haynes manual!

Thanks for all your time guys...now I just need a sub box to fit! Now where was that thread...