Hardwiring your radar detector, in this case a Valentine 1 (commonly referred to as a v1), is a required mod on pretty much any car. It saves you from using one of your available cigarette lighter sockets, allows you to mount the radar high up on the windshield and most of all, it gets rid of that ugly power cord that gets in the way of so many things. To hardwire a radar simply means that you will use an alternate power source available in the vehicle allowing the radar to turn on and off with the ignition. The wiring is hidden for the most part and the radar can be mounted high up on the windshield for maximum performance.
The good news is that hardwiring a radar detector is fairly easy to do and almost anyone can do it themselves with basic tools you should already have if you’re reading this post. Here are instructions on hardwiring a v1 radar on a 2008 BMW 335i convertible, but these instructions will apply to all e93 bmw models. On these vehicles, this install shouldn’t take more than 20-30 minutes and we will utilize the wire tap method as opposed to a fuse tap.
What You Will Need
· A small flathead screwdriver
· A set of hex head screw drivers of varying sizes
· A pair of small pliers
· Your Valentine 1 Radar with its standard windshield mount
· The hardwire kit from Valentine 1
· Read through this entire post first, and then start one step at a time.
· Keep screws and pieces in some kind of order on the floor of the car so when putting everything back, you won’t miss anything.
· We will be drawing power from the wiring harness which plugs into the dome light. This harness also powers many other sensors so be careful not to poke and prod around in other places. Doing so will cause fuses to blow. This is not a big deal, but it’s just unnecessary time wasted on replacing them.
· There is no need to have the car running or even have the key in the ignition until it’s time to test. There is also no need to disconnect the battery.
· A voltage meter is not necessary if you follow these instructions exactly. However, if you want to explore other power options or grounds, then feel free to use one.
· Make sure your radar is turned off.
Step 1: Remove Dome Light Fixture
A. Use your small flathead screw driver to pry into the outer rim of the dome light. It will come down a bit fairly easily, then you have to feel around the rim of the light to get all of the clips to come loose. Put some pressure on one at a time and eventually the dome light fixture will drop down and you will see the back side of it.
Step 2: Disconnect Wiring Harness
A. There is a wiring harness plugged into each side of the dome light fixture. Disconnect the one on the driver’s side only and the dome light fixture will now dangle on the right side of the car because it’s still plugged into the passenger side wiring harness.
Step 3: Ground Connection
A. Now it’s time to set up the ground connection. Luckily, there are 2 hex screws available directly above where the dome light fixture affixes so you can use one of them for the ground. Simply unscrew one about half way using a hex-head screw driver and insert the black wire (which has an open connector on the end of it) from your v1 hardwire kit. Then tighten the screw back up.
Step 4: Power Connection
A. The disconnected wiring harness has many wires going into it. You want to find and gently pull away (a little bit) the RED wire. This is the wire that we will be tapping into. Pulling it away a bit from the others allows you some room to work comfortable. Use the wire tap clamp supplied with the hardwire kit to first slide in the red power wire from the car’s wiring harness into the first chamber of the clamp. Then carefully insert the red power wire from your kit into the other chamber of the wire clamp. Once both are in, use your pliers to compress the metal edge into both of the wires, completing the wire tap. Now close up the clamp with its own cover.
Step 5: Testing
A. After both the ground and power wires are done, it’s time to test the radar. Use the flat phone cord to plug one side into the hardwire kit and the other into the radar. Turn on the ignition and power up the radar. If it powers up, you are good. With the radar still turned on, turn off the ignition and see if it powers down. Then turn it back on again and it should power right up. Other cars require having all doors closed and locking the car before power down and some will power down after a few seconds so test all scenarios before troubleshooting.
B. If you encounter issues, see if it will work with the wiring harness plugged into the dome light fixture. Otherwise, re-check your connections. If problems persist, you may have tapped into the wrong wire or blown a fuse along the way.
Step 6: Clean Up & Put Back
A. If everything works fine, now it’s time to hide the wiring. Disconnect the phone cord going into the radar and stuff all the wiring from the hardwire kit into the open space above where the dome light goes. There is plenty of space up there but using zip ties to have the wires neatly placed is always professional looking. It’s up to you. Just be sure to have the phone cord that goes to the radar have enough play to move the radar around to where you may want it now or in the future. Mount the radar exactly where you want it on the windshield. Fish the phone cord through the roofline where it meets the windshield and plug it in. Test again to make sure the radar works as it should.
B. If all checks out, make sure the hardwire kit wiring is tucked in the open space and then plug the wiring harness back into the dome light. Now put the dome light back into place. It may take a little force to put the light fixture back. Once this is done, this DIY is complete. You can enjoy your radar without having to manually turn it on or off and it will barely be visible from the outside of your car.