BMW e90 Radar Detector Fuse Box Hardwire Installation BY e90post.com’s bilbarstow

http://www.e90post.com/forums/showpost.php?p=284161&postcount=9

You will need to source the following from the local auto parts store- Add-A-Circuit Mini Fuse Tap and some appropriately sized mini fuses:

First- mount the V1 where you want it on the windshield, I chose just left of the mirror. The telephone wire can then be easily tucked between the headliner and the windshield with just fingertips to push it in. Route it across the windshield to the right side until you get to the place where the headliner meets the separation with the A-pillar cover (point A in second pic).

Put your fingers behind the black rubber molding at the door side of the A-pillar (at B) and push behind the seam from A - B. The headliner can be gently pulled out enough to open up the gap so that you can feed the telephone wire behind it. You can then push the headliner back in without showing any change or separation.

Route the telephone wire behind the black rubber molding until you get down to the glove compartment (third pic). Fitting it between the gap is pretty simple.

Once you are in the glove compartment (pic 4), placing the Fuse Tap and the V1 Hardwire adapter is very straight forward. Crimp the Fuse Tap red wire to the red wire of the V1 Hardwire Adapter. I also used the fuse for PDC / Homelink (third from right side in the second row of fuses - see the fuse map card in the compartment for details). Remove the 5 amp fuse that is in that slot and place it in the A slot of the Fuse Tap. I used a 3 amp fuse for the V1 because that was the lowest one I had - even though the V1 only requires a 1 amp fuse. I have since replaced the 3 with a 1. For the black ground wire, crimp on an eyelet connector, and I drilled a hole in the metal brace and used a #8 bolt and nut to attach it, secured with some LockTite. (NOTE: You can also use the Torx head bolt that is circled below to avoid drilling holes)

I mounted the Hardwire adapter to the sidewall of the fuse compartment using the supplied Velcro (pic 5). The phone wire plugs in to the Hardwire adapter in the main slot. If I choose to later, it will be very simple to add the Remote Display - just plug it in to the Accessory slot.

Very simple installation - Thanks very much to Josh49's original post for the initial info - I hope that this helps any of you considering doing this for yourself.