Accessory power

[smitham]

Are there any factory installed accessory power installed in the H3? I want to hard wire my radar detector and don’t really want to cut up the factory harness. My last car (corvette C5) had this option (inside a compartment there were there wires a switched positive, a positive and ground, all you had to do is tie in the new wires and you were ready to go) it was great. Any help would be great.

[smitham]

Are there any factory installed accessory power installed in the H3? I want to hard wire my radar detector and don’t really want to cut up the factory harness. My last car (corvette C5) had this option (inside a compartment there were there wires a switched positive, a positive and ground, all you had to do is tie in the new wires and you were ready to go) it was great. Any help would be great.

[f5fstop]

The infamous Radar Detector wires, located just above the I/P fuse block. They were handy for hard wiring in the Escort or Valentine, the two favorites of the Corvette owner.
The Hummer has four wires under the I/P on the driver's side, but there is no Ignition Hot, only a battery hot, ground, brake signal and trailer brakes.

I can tell you what I did which was not that invasive to the wiring.
I mounted the radar detector just to the left of the rear view mirror. Then ran the two wires under the top windshield trim to the driver side A-pillar.
(The A-pillar molding is held in place with one screw, under the cover, and some retaining clips. Just remove the one screw, and pull, very easy to remove.)
Inside the A-pillar is a wiring harness that contains some wires, depending on your option content of the vehicle.
With the dimming/temp display rear view mirror:
Ignition Hot wire: Dark Blue/White stripe this wire is run through a 10A cruise/misc fuse, via the RUN/CRNK relay and supplies B+ whenever the ignition is in run.
Ground: Black/White stripe

If you have OnStar, do not tap into any of the following wires:
Brown/white (Keypad RED LED signal)
Yellow/Black (Keypad GREEN LED signal)
Dark Green/White (Keypad call answer, OnStar, Emergency signals)
Light Green/Black (this is the OnStar supply voltage for the OnStar mirror switches and I might be only five volts; not sure).
Again, I do not recommend tapping into any of the OnStar function wires.
Ground for the OnStar functions is also a Black/white stripe, but it goes directly to a ground point so this is NOT a problem.

If you have the sunroof, you can tap into the same wires I used:
Yellow: Ignition Hot through the S/ROOF/FRT/WPR fuse fed via the RAP relay, so the detector stays on after the ignition is off, but goes off when a door is open (retained accessory power function).
Ground: Black

I took the tape off the wire protector conduit, and used small butt end connectors to tap into the wires. Then I re-taped the conduit, installed the A-pillar. I did have to epoxy the suction cups to the window. For some reason, even new suction cups would not adhere to the window...drove me crazy. So, I just applied some epoxy, let it sit over night, and attached the detector, and in six months, it has not fallen.