# "Non-destructive" V1 hardwire for E46s



## cchan (Sep 19, 2002)

Hi all - There are a number of great DIYs on hardwiring radar detectors off of the switched 12V power on the garage door opener (UGDO) wiring harness in E46s. But, using the supplied scotch-lok wire taps has apparently not always been reliable (if not pushed in enough, it won't have a solid connection, or if too far might cut all the way through the wire). Plus a lot of people worry about potential warranty issues (whether true or not). So, I figured out a way to tap into the UGDO wiring harness using connectors that fit rather than cutting into the car's wiring, and is completely removable should it be necessary.

This requires basic wiring and soldering ability, so if you're not so inclined then I guess scotch loks are the easier route for you. Since other DIYs have covered this, I won't go into pulling out the dome light and panel and finding the wiring harness for the UGDO here.

My solution was to get a computer fan extension cable from Fry's for $1.29 (photo 1). It has 3 wires, and the male connector end with the pins will fit perfectly into the connector at the end of the UGDO wiring harness. It might be best to test fit the cable (photo 2), and then mark which of the 3 wires is the +12V (connects to the green/blue) and ground (connects to the brown wire). In my case, the black extension wire became +12V and yellow ground. I used colored markers to put a red + and black - on the extension cable's plug to help me remember.

Now if you don't have the UGDO, you can just cut off the other end of the cable and connect the power leads from the V1 module appropriately. But if you do have the UGDO, we will tap into the extension cable which will run inline from the wiring harness to the UGDO. I figured that tapping into a cheap $1.29 cable was better than the car wiring.

But, notice in photo 3 that the UDGO socket is keyed (the notched side is the +12V switched wire), and our cheap cable is a plain rectangular shape. (photo 4 - harness plug on left, extension cable on right) No worries, just use a file or Dremel, and sand down the female end of the extension cable until it fits the UGDO plug. In my case, I had to sand down the little "legs", the corner notch, as well as the top of the plug. Just keep working at it until it fits the UGDO plug (photo 5).

Now might be a good time to test fit and make sure the UGDO works with the extension cable before we splice into the cable. Plug the pin end into the wiring harness, and the other end into the UGDO, turn on the car and make sure your garage door opens/closes.

(continued in next post)


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## cchan (Sep 19, 2002)

Now to splice into the extension cable. There are two approaches, you can either splice the V1 hardwire module, or if you are more advanced electronically and not using the remote display, you can skip the module entirely. I skipped the module since I was not going to run a wire down the A-pillar for the remote display. The UGDO is protected by a 5 amp fuse in the glovebox, so I don't think an additional fuse is really necessary.

I cut about a 1.5-2 foot length of the telephone cord supplied with the V1 (any cord will do, but the V1 is black and has a nice strain relief on the plug). We need to figure out which of the 4 colored phone wires are ground and power to the V1. In photo 1, if we look at the phone socket on the V1 and number the pins from 1 to 4 going left to right, ground is #2 and +12V is #3. Look at how the phone plug would go into the socket, and then see which of the two middle wires is which.

To do the splice, I cut the +12V and ground wires about 1/3 of the way from the male pin end that connects to the wiring harness. We want to leave more of the other end free so that it can reach the UGDO socket. (If you don't have the UGDO, you can cut further away from the pin end to give you more wiring to play with. I only cut the two wires, and left the third middle wire intact (not sure it is used, but no reason to mess with it). (photo 2)

Strip the appropriate wires in the phone cord as well as from the fan extension cable and twist/solder them together. I decided to heat shrink around the soldered twist connections, but electrical tape will do (or other reliable electrical connection methods). (photo 3)

The completed "custom" wiring module is shown in the 4th photo. Plug the pin end into the wiring harness, female end into the UGDO, route the phone cord around the headliner, and then close everything up. If all went well, the V1 and UGDO should work.

The 5th photo shows wiring using the V1 hardwire module instead of the "direct" method described above.

Hope this helps, good luck!


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## Hercules (Jul 15, 2002)

Nice little DIY -- too bad I already wired and I'm lazy to redo it


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## xclone (Sep 22, 2005)

Here's my hardwire install for a V1 and remote indicator for a 2002 530i. 

I don't have enough pictures to justify a writeup, but will post the pics of the completed install. If you want more information on how I did it, PM me and I will be happy to help.

Pic 1 - Final mount of V1.
Pic 2 - Final mount of remote indicator
Pic 3 - Fusebox tap and V1 accessory power module mount
Pic 4 - Shot of the remote indicator with the dremeled back so it "wraps" the lower lip of the instrument cluster.

In all, took me about 1 1/2 hours and cost $10 for the fuse tap and velcro.

The mounting place of the remote indicator was a tough call for me. I didn't want it blocking the instrument cluster but also wanted it hidden and within easy viewing. The current mount is great because I can angle it easily (velcro). The only downside is when turning left, the steering wheel obstructs the visual.

Enjoy!


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## hockeynut (Apr 14, 2002)

Can't wait to try this out @ home!

I am not too keen on tapping into my existing wiring, this sure looks like it will do the trick...thanks!


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## icemanjs4 (Dec 1, 2004)

hockeynut said:


> Can't wait to try this out @ home!
> 
> I am not too keen on tapping into my existing wiring, this sure looks like it will do the trick...thanks!


Really, the tapping into the existing wiring is so minimal that I wasn't worried at all. It worked perfectly the first time out and I've never had any problems since.

However, that's a nice DIY you posted, and certainly would make a nice alternative.


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## hockeynut (Apr 14, 2002)

Opened up my overhead lighting (its a 330 convertible) and I think I found a wire I can use...pls see http://www.bimmerfest.com/forums/showthread.php?t=155620

Does that look the right one?


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