No power to headunit?

evoman · Post by **evoman** » Tue Mar 24, 2009 8:50 pm

Hey everyone, sorry for the retarded question but it's pissing me off and I can't really find any more clues anywhere.

The previous owner of my car obviously had a bit of a mad arse system installed, but has taken it all out and put the stock speakers back in - but didn't leave it with a headunit.

Anyway, I've managed to get hold of a mates old(but still pretty new) headunit which I know works 100% fine(we have tested it). However after wiring it all up, it just doesn't want to work and doesn't seem to get any power.

I'm 100% certain the wiring and the earthing is fine. After locating the correct fuse in the egnine bay I checked it and it appeared fine, but I also swapped it with the brake light fuse(that I know works) to double check and still the headunit isn't batting an eyelid.
The car has an immobiliser fitted and also appears to have a bit of a funny issue with the reading lights not always working - so I'm not sure if they could be related in any way?

I haven't been able to get hold of a testlamp just yet, but even if it proved there was no power getting through I don't think that is going to help me either.
Has anyone got any more ideas?

mr-charisma · Post by **mr-charisma** » Tue Mar 24, 2009 9:28 pm

have you made a Cold Air Intake box recently?

Tippin · Post by **Tippin** » Tue Mar 24, 2009 9:47 pm

this is for an fto correct? just wondering because of your username

Post by **I8A4RE** » Tue Mar 24, 2009 9:49 pm

where do you live? if you live near me bring it round and ill take a look for you.

if not, then you need to buy a test light or multi meter and test for power

Astron_Boy · Post by **Astron_Boy** » Tue Mar 24, 2009 9:50 pm

2 posts, zero help....

Have you got the correct wire for positive?
There are a lot of wires behind the headunit, it's possible you may have the wrong one.
Best way to find out, is a multimeter and just find the 2x12V lines, then ACC off and fine the 1 12V line.
Ground is the frames side.

edit, haha, you beat me Simon.

Tippin · Post by **Tippin** » Tue Mar 24, 2009 10:00 pm

MAD-FTO wrote:2 posts, zero help....

well sooooooooooooorrrrryyyy hahaha

i was gettin to it, some cars (not many though) have a different colour accessories cable, usually they are red but when i was wiring up my mates headunit in his sh!tbox camry it was black and i spent 2 hours wondering wtf. guess this is not your probably though lol

make sure your grounding isn't loose or dirty

evoman · Post by **evoman** » Tue Mar 24, 2009 10:02 pm

Thanks for your help MAD-FTO and I8A4RE.
Yes I am an FTO owner lol...but love the evo's

Probably should update my avartar to say I'm in NSW.

Anyway, I am sure the wiring is fine. I have done it plenty of times before in other cars, have tripple checked this one and I can't see anything wrong. Guess I will just need to get hold of a test light or multi meter

Post by **Bennoz** » Tue Mar 24, 2009 10:04 pm

Get a multimetre & start measuring current from the head unit into the loom. When you find current, you find your issue.

Also checked the fuse in the back of the head unit?

Astron_Boy · Post by **Astron_Boy** » Tue Mar 24, 2009 10:08 pm

tippin9 wrote: well sooooooooooooorrrrryyyy hahaha

So you should be

Had a brain spaz and got pissed off for a second

Where in Sydney are you?
If you would have asked a week ago, could have told you which color wires you needed ad I had the interior centre section stripped.

Could always come to the bonfire and we could have a look, good way to meet people to

mr-charisma · Post by **mr-charisma** » Tue Mar 24, 2009 10:14 pm

tippin9 wrote:
MAD-FTO wrote:2 posts, zero help....
well sooooooooooooorrrrryyyy hahaha

i was gettin to it, some cars (not many though) have a different colour accessories cable, usually they are red but when i was wiring up my mates headunit in his sh!tbox camry it was black and i spent 2 hours wondering wtf. guess this is not your probably though lol

make sure your grounding isn't loose or dirty

I'm not .. at least I thought it was funny..

evoman · Post by **evoman** » Tue Mar 24, 2009 10:15 pm

Yeh I guess I must have screwed up somewhere, will just have test and find out.
Thanks anyway everyone.

Astron_Boy · Post by **Astron_Boy** » Tue Mar 24, 2009 10:30 pm

mr-charisma wrote:
tippin9 wrote:
MAD-FTO wrote:2 posts, zero help....
well sooooooooooooorrrrryyyy hahaha

i was gettin to it, some cars (not many though) have a different colour accessories cable, usually they are red but when i was wiring up my mates headunit in his sh!tbox camry it was black and i spent 2 hours wondering wtf. guess this is not your probably though lol

make sure your grounding isn't loose or dirty
I'm not .. at least I thought it was funny..

you know, I just got your joke.
hadn't read that thread until 2 sec ago.

mr-charisma · Post by **mr-charisma** » Tue Mar 24, 2009 11:09 pm

MAD-FTO wrote:
mr-charisma wrote:
tippin9 wrote:
MAD-FTO wrote:2 posts, zero help....
well sooooooooooooorrrrryyyy hahaha

i was gettin to it, some cars (not many though) have a different colour accessories cable, usually they are red but when i was wiring up my mates headunit in his sh!tbox camry it was black and i spent 2 hours wondering wtf. guess this is not your probably though lol

make sure your grounding isn't loose or dirty
I'm not .. at least I thought it was funny..
you know, I just got your joke.
hadn't read that thread until 2 sec ago.

gotta be quick..

evoman · Post by **evoman** » Wed Mar 25, 2009 5:19 pm

Alrighty. Well I got hold of a test light and found that there is no power through the constant wire, but there is through the accessory wire

The constant wire is coming directly out of the loom so I'm a little puzzled why there is a problem, especially considering I checked the fuses last night.

As a short term workaround I have just wired up the accessory cable to the constant on the headunit, but obviously this means the headunit resets every time I turn it on again so that's not really ideal.

Any ideas why I have no power through the constant?
Damn antenna doesn't seem to work either

Post by **I8A4RE** » Wed Mar 25, 2009 5:50 pm

evoman wrote:Alrighty. Well I got hold of a test light and found that there is no power through the constant wire, but there is through the accessory wire The constant wire is coming directly out of the loom so I'm a little puzzled why there is a problem, especially considering I checked the fuses last night.

As a short term workaround I have just wired up the accessory cable to the constant on the headunit, but obviously this means the headunit resets every time I turn it on again so that's not really ideal.

Any ideas why I have no power through the constant?
Damn antenna doesn't seem to work either

How do you know that the so called "constant power" wire is that? (im talking about on the car side not the stereo side).

But lets say you have the correct wire.
I reckon you have blown a fuse.
Turn your ignition on
RUn your test light over all fuses under the dash
If you have power on one side of the fuse and not the other fuse has blown. Its much quicker than pulling them out lol