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mc87yanks
05-12-2006, 06:59 PM
Alright, I asked this question in another thread and no one responded, so I'll ask in a new thread.

The 12v red wire running to my headunit is dead. There is absolutely no power coming from it. Because of this, the head unit has no memory and the electrical does not work when the engine is not working. Any ideas?
03SilverBullet
05-12-2006, 07:08 PM
Did ya check the fuse?

Bad wire?
txdproject
05-12-2006, 07:08 PM
that wire should have power.24/7 im running my radar on it .
mc87yanks
05-12-2006, 07:21 PM
The wire has always worked. It was connected to a CD changer that I removed. After I removed it, their was no longer power running to it.

I checked all the fuses and they seem fine. Does anyone know what fuse it would be if it was in fact the fuse?
johnblaze94
05-13-2006, 02:49 AM
The red wire should be powered only when the key is turned to acc. The yellow wire should be constant 12V
wagonofhell
05-13-2006, 03:52 AM
The red wire should be powered only when the key is turned to acc. The yellow wire should be constant 12V
that sounds about right to me, I have never seen a red have constint power on a manufacers setup.
txdproject
05-13-2006, 04:49 AM
well maybe im just the odd one out but i ran my radar of the thick red( positive) and the thick black (neg) and i have constant powere regardless of the key being in
mc87yanks
05-13-2006, 02:10 PM
well maybe im just the odd one out but i ran my radar of the thick red( positive) and the thick black (neg) and i have constant powere regardless of the key being in

Yeh, from all that I've read about the Elantra, the red line is a 12v constant line. The yellow should be the line that only works when the key is in ACC. But isn't the black the ground?
Doohickie
05-13-2006, 03:27 PM
neg = ground.
mc87yanks
05-13-2006, 03:41 PM
Haha, don't know electrical all that well. Anyone have any ideas why there wouldn't be any power in the line?
BColeman
05-13-2006, 06:01 PM
One idea:

When you disconnect the CD changer power from the CD Player power, did you leave any wire behind??? If you did, it could be shorting out on some metal or something, and you aren't getting power.

FYI:
Red - 12V Acc Turn On Power
Yellow - 12V Constant Power
Black - Ground

Most cars over the last 10 years or so have been built with separate wires for ACC and Constant Power. My '90 Colt did not have the yellow, everything was run through the Red power lead.
Vampyrate
05-13-2006, 06:16 PM
well maybe im just the odd one out but i ran my radar of the thick red( positive) and the thick black (neg) and i have constant powere regardless of the key being in
my glow pedals were running off the red wire and it was a constant power in my 01 GLS
mc87yanks
05-14-2006, 01:03 PM
One idea:

When you disconnect the CD changer power from the CD Player power, did you leave any wire behind??? If you did, it could be shorting out on some metal or something, and you aren't getting power.

FYI:
Red - 12V Acc Turn On Power
Yellow - 12V Constant Power
Black - Ground

Most cars over the last 10 years or so have been built with separate wires for ACC and Constant Power. My '90 Colt did not have the yellow, everything was run through the Red power lead.

Everything I've read from Hyundai says that the red wire is a constant 12V that controls memory and power when the engine is off.

Either way, I'm not getting power from the red when the car is on or off. The Yellow line only works when the engine is running.
Doohickie
05-14-2006, 01:34 PM
Here is the official scoop:

http://i42.photobucket.com/albums/e341/Doohickie/XD2Audio.jpg

Two power wires coming from the Passenger Compartment Junction Block:

Fuse 25, 15 amps, Hot at all times, Red, 1.25 mm wire.

Fuse 9 (hard to read, but I checked it), 10 amps, Hot in Acc or On, Yellow, 0.3 mm wire.

Instead of depending on word of mouth, go to the source, Hyundai WebTech. This guide will help you learn everything you need to get started (http://www.dfwhyundais.com/diy/DIY-WebTechGuide.html).

Bottom line: If the read wire is dead, check Fuse 25 in your Passenger Compartment Fuse Box.
mc87yanks
05-14-2006, 02:10 PM
Thanks so much man. I pulled nearly every fuse except for that one. Just went out to the car and the thing is toast. Thanks so much for your help.

Also, do you think it blowing is only natural? Or could it be that the head unit needs more power or something?
Doohickie
05-14-2006, 02:22 PM
What do you have hooked to it?

Blowing fuses is never "natural". If it blows again, you need to find out why.
mc87yanks
05-14-2006, 02:33 PM
Actually, we probably touched two of the wires together. But it's just a normal Alpine HU, so I doubt it has anything to do with that. I'm assuming if I touched the yellow and red lines together that the fuse would blow, right?
mlrman
05-14-2006, 11:45 PM
Actually, we probably touched two of the wires together. But it's just a normal Alpine HU, so I doubt it has anything to do with that. I'm assuming if I touched the yellow and red lines together that the fuse would blow, right?

I do not believe in coincidences.....

1) head unit worked before

2) then you removed the CD changer

3) head unit does not work

sounds like you crossed a hot and ground wire.

now, if it blows again, definitely do some more checking. like doohickie said, fuses don't just naturally blow. They are a safety precaution to prevent more serious damage when there is a problem.

P.S. always take the two minutes to remove your ground wire from the battery to avoid these problems.
chaos GT
05-15-2006, 01:47 AM
I do not believe in coincidences.....

1) head unit worked before

2) then you removed the CD changer

3) head unit does not work

sounds like you crossed a hot and ground wire.

now, if it blows again, definitely do some more checking. like doohickie said, fuses don't just naturally blow. They are a safety precaution to prevent more serious damage when there is a problem.

P.S. always take the two minutes to remove your ground wire from the battery to avoid these problems.
agreed... the hot wire wouldn't even have had to touch a ground wire, pretty much any metal on the car would do it too.
johnblaze94
05-15-2006, 03:55 AM
Sorry, i assumed you were splicing in after a wiring harness like most people do.
Doohickie
05-15-2006, 10:11 AM
Touching yellow to red won't blow the fuse; the Red is 12 V and the Yellow is either 12 V or not connected to anything. 12 V touching 12 V is no big deal.

You probably touched the 12 V Red to some metal. Virtually all the bare metal in the car is ground. If you take a 12 V wire and ground it, you *will* blow the fuse. Sounds like maybe that happened.

In the future (or for anyone else doing this kind of work) you can either pull the 9 and 27 fuses from the Passenger Compartment Fuse Box or just to be safe, pull the master Power Connector from the fuse box. You can see the Power Connector in the image below. Pulling that disconnects all the power for the fuse box. Once pulled, you can rotate it 180 degrees and put it back in so you don't lose it. Just bear in mind it fits in that way, so if you remove it and put it back and nothing works, you can try to pull it out, turn it upside down and put it back in and things should work.

http://i42.photobucket.com/albums/e341/Doohickie/IPFuseBox.jpg