Radio Killing my Battery...

[saf26]

Hey guys, I just recently set up an aftermarket HU and When I put the adapter harness together I matched up the red power from the HU with the red from the car, and the Yellow wire from the HU with the yellow wire from the car. When set up like that though, the radio resets everytime I turn the car off. So I switched the wires because I read that VW does the colors in reverse. When I matched the yellow with red and vice versa it worked perfect. It didnt reset at all. But now, my battery is dead and thats no good. I read about the 75x terminal, but I'm still kind of unclear on what to do. Any help would be awesome. Thanks

[Mr_Diesel]

Welcome to Dubnet! You've come to the right place for this, my friend. I have installed dozens of decks in Volkswagens. I just need to know what year and model your car is. You've probably hooked the "switched" power wire or the "ACC" wire up to a constant 12V supply. I think this is the yellow wire on most aftermarket decks. Switched means it gets turned off with the key and as long as the red wire remains powered (12V constant) the deck should not reset.

[saf26]

Hey, thanks for the welcome. I drive an 01 Jetta GLX, and the head unit is a JVC. I'm so stumped with this, I thought i've tried every wire combo. Thank you

[Mr_Diesel]

I was afraid you were going to say that... does your car have radio controls on teh steering wheel? Also... does your car have the following wires?

Red/White
Yellow/Red
Brown

They should be larger that most of the other wires in the harness. If no... does it have a solid orange wire?

[saf26]

Yes, my car has the three wires you mentioned, and yes I have steering wheel controls. The way it was originally hooked up, was the red wire from the HU connected with the battery wire (red/white) on the oem harness. The steering wheel controls were spliced into this red wire. The yellow wire on the HU went to the ignition wire (yellow/red) in the oem harness. And lastly the black wire from the HU went to the ground(brown) wire in the oem harness. This setup did not kill my battery, however it reset everytime i turned on the car.
I switched the wires from the HU so that it was, red wire from HU into ignition(yellow/red) wire, and the yellow wire from HU to battery wire(red/white). I left the steering wheel controls spliced into the battery wire. This setup saved presets, but killed my battery overnight.
Yikes....I know its a mess, sorry

[Mr_Diesel]

The way it was originally hooked up, was the red wire from the HU connected with the battery wire (red/white) on the oem harness. The steering wheel controls were spliced into this red wire. The yellow wire on the HU went to the ignition wire (yellow/red) in the oem harness. And lastly the black wire from the HU went to the ground(brown) wire in the oem harness. This setup did not kill my battery, however it reset everytime i turned on the car.

The text I quoted from your post is how it must be hooked up. Do you have a voltage tester or a test light? See if there is power on the red/white wire when the ignition switch is off and the key is removed. From what I remember there is some kind of power "bus" that is screwing up the standards here. If there is no juice on the red/white wire when the ignition is off, then you will probably need to run a wire directly from your positive battery terminal. Don't worry... it's not as hard as it sounds. Just make sure you get a fuse link from radio shack (like 4 bucks). You'll probably need about 6 feet of (at minimum) 14 gauge wire. That should solve your problem.

Before you do that it would probably be a good idea to check to see if the "acc/switched" wire has power when the key is off. It could be that the steering controls are providing power to the switched circuit when the key is off somehow. If that's the case, try bypassing the steering controls all together. By going aftermarket you probably loose most or all of the function of those buttons anyway.

Good luck and keep me posted.

[zukgod1]

Sounds like Mr Diesel is steering you the right direction here.

The only thing I may do differently is to find a non keyed circuit behind the fuse panel and tap there instead of running to the batt. Either way will work I'm just not a fan of working a bunch of extra crap to the batt terminals. You will need a in-line fuse holder either way..
Good luck and keep us posted.

[Mr_Diesel]

I think some company makes a little tab that goes over a wire and when you crunch it down metal teeth sink into the wire. That allows you to "tap" into a wire without splicing or cutting the insulation. Perhaps you could get some of those and just tap into the main accessory wire behind your fuse panel. I agree, that this is a better idea that running a battery feed. Check radioshack for availability.

[zukgod1]

Those are pretty good as long as ya dont get one to small, if it's to small it will cut most of the strands in the wire and will create allot of Resistance.
If you get the correct size for the gauge of wire your working with though they are great. I like to fill them with blk silicone before I place them so after the "Tap" it's all sealed.

[saf26]

Ok guys, here's the scoop so far. It seems that the color of my headunit wires are actually the opposite of VW colors. Therefore red doesnt match with red, and yellow doesnt match with yellow. When I crossed them however the head unit memory worked (making it clear to me that the battery wire was getting power) but my battery died. I didnt know why my battery was dying (still dont actually) since I properly put the switch wire from the HU into the 12v ignition wire on the factory harness. The only thing I could think that was doing it was that I think its like a "key in" switch or something? Meaning that as long as the key is in, my radio will stay on after the car is turned off. So maybe it wasn't working properly and still draining power when I took the key out? So after 2 mornings freezing my ass off jumping my car, I went to radio shack and bought some wire. I ran a wire from the switch wire on my HU under my dash and to the 75x terminal. Then I taped off the ignition wire on the VW, and prayed it would work. This morning, no dead battery, presets still work, and I'm a happy camper.:-D

Thank you guys for helpin out.

[zukgod1]

That's what we are here.
Glad it's working now.