Made Bike Repairs

I installed a 12V DC power port in the trunk of "The Beast" to charge my cell phone while streaming music on rides. It plugs into a hot power connector in the trunk lid that is for the optional trunk light. I used to carry my cell in the left faring compartment, but ran into a couple of problems. First, the physical size of my current phone barely fits, and second overheating my phone on hot sunny days. The cover of the compartment is black so it is like an oven. Keeping my cell in the trunk has worked well, until last Friday, when I plugged in my charger and it was dead. I did some quick basic troubleshooting and sure enough, the power port was dead. Being off yesterday, I dug into the problem.

First I consulted and then printed the wiring diagram pertaining to the trunk electrical and lighting systems. The circuit was surprisingly simple. Power from the 15A fuse #31 goes up to the trunk and splits off between the keyless lock controller/receiver and the plug for the optional trunk light. I started to check the fuse when it dawned on me that the fob and locks were working fine. But when I opened the trunk, the locks would not respond to the fob. Hmm, I think I remember it working regardless. Sure enough, as soon as the trunk lid was at about 45 degrees, it stopped working even though the lid was not latched. I plugged in the charger which has indicator lights on it and as I closed the lid I peeked inside and BINGO! the lights came on as the lid came down. I was pretty sure it always worked with the lid all the way up, so I checked the wiring diagram again to make sure there wasn't a lid position sensor. None as I suspected. That meant a broken wire that was opening and closing the circuit with movement of the lid, and that only happens in one place... where the wiring harnesses flex by the hinge on both sides. But which side?

I started by removing the inner cover of the trunk lid to expose the connectors for the power port and the keyless lock controller/receiver. I unplugged both which let me set the inner cover aside completely out of the way. I then carefully sliced open and unwrapped the harness to expose the wires. As a classically trained electronics technician, I have the skills and dexterity to do this without causing damage to any of the conductors in the bundle. It takes a light touch with a razor knife and patience. The wire supplying 12 VDC power to the controller/receiver and trunk light connector is red with a yellow stripe and green bands matching the call out in the wiring diagram. The wires went down the harness to the right. I sliced open and unwrapped the harness the entire exposed length by the hinge, and what do you know? The red/yellow wire in the bundle is broken cross-ways, and acting like a hinge with a little piece of insulation not broken. When the lid came down, the cross section of the copper conductor closed like a switch. Now to fix.

Usually a broken wire requires two splices to fix, and I was prepared to do this, but by moving the wire around in the bundle, I easily gained the slack I needed. I decided to do a "Western Union" style splice to maintain the profile of the wire in the bundle.

A proper "Western Union Splice" is stronger tension wise than a pigtail

 

Because this is a hot battery lead, I disconnected the battery and pulled the fuse just to be sure everything was dead. I stripped off just enough insulation to give me enough copper wire to form a good mechanical splice. I then slipped a piece of heat shrinkable tubing over one of the wires and out of the way, made a good mechanical splice, then soldered the connection. The heat shrinkable tubing was slid up the wire to cover the splice and shrunk in place with heat from a small butane torch. It came out perfect and the circuit testing for the power port and keyless locks were now operating as expected, regardless of trunk lid position.

The spots of the harness that I opened up needed to be re-wrapped. At the flex points, Honda had placed the wires in a plastic sleeve to allow for movement. That was not reusable, so in it's place I used small lengths of bicycle tire inner tube, which has powder inside that should allow the wires to move as needed. I sliced it lengthwise, wrapped it around the wires, and taped it in place. The entire length of exposed harness was then wrapped in 3M 33+ Electrical Tape. When I was done, it was impossible to tell it had been molested.

The repaired harness by the right trunk lid hinge.

 

I spent the next 45 minutes or so re-connecting the battery and putting everything back together. A final test proved everything worked as intended, and I rode The Beast in to work this morning. There is a benefit ride coming up on September 10th, and being able to stream music and keep the phone charged is important.