Car won't start with headunit turned off!!
Thread Starter
Drifting
Joined: Jun 2003
Posts: 1,748
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From: CA
Car won't start with headunit turned off!!
Ok, this is one of the strangest things I've ever come across. I installed a new alpine deck in my car this weekend (02 z06), and ended up using the three wire harness in the passenger footwell (yellow, orange and black I believe). Anyway, after the install was complete the car would not start. The lights, gauges, etc. all worked fine, but when you turned the key to 'start' there was nothing, no starter relay clicking, etc. So I replaced the battery to no avail, and retraced my steps several times. As I was about to give up I turned the stereo on just to see if it was still working (it was) and tried cranking the car over one more time. To my suprise it fired right up. I experimented with the stereo on/off and everytime the car starts as normal when the headunit is on, and does nothing when its turned off. The only thing I can figure is the wire I used from the footwell has something to do with the immobilizer (or whatever the stock alarm system is called). Has anyone else experienced this? Appreciate the help.
Le Mans Master
Joined: Nov 2004
Posts: 8,718
Likes: 20
From: Dyer IN
Cruise-In IX Veteran
Thats crazy, just curious have you tried unhooking the radio and by chance did u blow a fuse in the fuse box, and somehow its back feeding power when the radio is on allowing car to start
Burning Brakes
Joined: Feb 2001
Posts: 793
Likes: 2
From: Milwaukee & Long Beach WI & CA
Very strange. I recently installed a new head unit and used the yellow and orange wires in the passenger footwell for power as shown in the Valentine one install tech tip
I didn't use the black as I grounded to chasis. But still, those wires should work fine. I'm not sure what's going on.
I didn't use the black as I grounded to chasis. But still, those wires should work fine. I'm not sure what's going on.
Thread Starter
Drifting
Joined: Jun 2003
Posts: 1,748
Likes: 0
From: CA
I appreciate the advice guys, I'm going to be checking all the fuses soon and see if that may infact be it. Also, those are the exact wires I used from the photo above. Any idea what fuses it could have been? Thanks
Melting Slicks
Joined: Dec 2004
Posts: 2,394
Likes: 0
From: Bay Area CA
Hmm thats crazy .. .think penta is on to what is happening, I tapped just the yellow wire myself for my install and did not have issues. Hope you get it worked out and it is something simple.
Fej
Fej
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Thread Starter
Drifting
Joined: Jun 2003
Posts: 1,748
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From: CA
Hey guys, I think penta may be correct. After going over the situation in my head here is why I believe that is whats happening. I went home at lunch today and checked on a hunch and found out that I am not retaining any stations/etc. Therefore, I believe my source for constant 12V has blown a fuse and when I turn the stereo on that line is receiving 12V from the acc. wire (run to the pass. footwell) through the stereo. Obviously the fuse that's blown must control something which is keeping the car from starting. However that would explain the car not starting as well as the head unit not retaining any settings. I'll update everyone tonight if I get home in time to track down the fuse.
Le Mans Master
Joined: Dec 2005
Posts: 6,420
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From: "This is not a psychotic episode, but a cleansing moment of clarity."
Originally Posted by corvette-pilot
Sounds like a really cool anti-theft feature 
But I'd hate to be driving down the freeway and turn off the radio by accident. 
Thread Starter
Drifting
Joined: Jun 2003
Posts: 1,748
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From: CA
Hey guys, sorry I didn't report back. I checked all the fuses and the only blown one I found controlled the cigarette lighter. I replaced it, but it did not solve the problem. So I ended up just running the constant 12V directly to the battery and found another switched 12v closer to the ignition. I didn't have time to search any further into the matter as I was afraid I would not be able to start my car at an inopportune time (away from home). Thanks again for all the suggestions, I guess this will get filed in the unsolved mysteries section 
Melting Slicks
Joined: Jan 2004
Posts: 2,992
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From: Henryville IN
Same thing happened to me! I found that I had the yellow and orange wires reversed. In other words the one that was supposed to be hot all the time was wired to IGN and the one for IGN was wired hot all the time. Not sure why that made it not start but I flipped them and no more problems. So just a try flip your radio wires on the orange and yellow. I used all 3 on mine even the ground.Maybe the same thing
Last edited by ABNVET.I; Jul 19, 2006 at 11:07 PM.
Thread Starter
Drifting
Joined: Jun 2003
Posts: 1,748
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From: CA
Wow, you know whats odd, I discovered the same thing when I was switching power sources. I just assumed it would not make any difference though given how strange the car was acting. Thanks for the heads up, I'll try this out over the weekend!