Trying to find the wiring harness [2003 Superglide] that runs down the 'backbone' to get to the electrical plugs to extend handlebar wiring. I have the battery out and shining a flashlight down there and cannot see it. I have read that it sometimes goes behind the rear fender but after checking with the light it's not there. Can someone direct me please ?...b.

 

I did this on my 02 last year... the harness actually runs down the interior of the frame. Now here is what I found worked best: First put the bike on a jack and unbolt the rear shocks at minimum, I removed my whole rear wheel, because for some unfathomable reason, HD ran the wiring "service loop" (at least on mine and I think the 02 and 03 were the same) and bundled it up behind a panel on the UNDER SIDE of your rear fender... go look, you'll find it! (now remove it and pull the loop of wire out the back, this makes the next pulling step work much better. I also had the best luck with removing tank bolts and sliding my tank back as far as I could. this will open up the "hole" in the neck a bit more. Once the tank is back you should be able to see where the wiring goes, also look for a rubber plug on the right side of the neck (I removed by cutting the zip tie from the left side and prying the plug out). Follow wires from your headlight, etc down towards the left side of the neck. Now grab a hold of the wire bundle and start a-pullin (gently but with authority) towards the front. The plugs are staggered and will start to come out of the neck as you pull. I highly recommend that BEFORE you cut anything, you watch a couple of videos or search on here for how to de-pin your connectors, you can then pull the factory wiring through your new bars (may not even need to extend anything...I went to 10 inch bars from factory size and their was plenty of wire tucked in the neck) and reconnect it all with factory connections. Getting these connectors out and doing the wiring are the easy parts. The hard part comes when you have to stuff it all back in... basically push it down the neck and pull it from under the fender (at the same time if you have a second set of hands) until its all back in the neck, then roll the loop back into the fend, put the cover on, etc. I am sure I have made this sound like a walk in the park, it will not go nearly as smoothly as this makes it sounds. Get ready for an adventure.

 

hmm, maybe mine is different. All i did was slide the tank back til i saw where the connectors were, then unplugged them and went from there. I got an 08 FXSTC though. Had to unhook the quick fuel connector from the tank first, then i covered the top of the rocker boxes with a piece i cut out of a cereal box so that when im sliding the tank back it didnt scratch them. Took the main bolt out that holds the tank on and just pulled it back. Had just enough room if i slid the tank as far back as i could to get ahold of the connectors. I did not have to take the tank off like alot of people say. Maybe this is model specific. The biggest problem i had with extending my handlebars was getting the pins out of the connectors and back into the connectors. There is a hole for a paperclip so that you push in and the pin is suppose to pop out. Some of them did, and some of them didn't. Theres a little plastic piece that you have to make sure is set in there correctly when putting it back together....if you dont the pins will feel like they are clicking back into place but arent. Theres a little trick to it, i figured it out after messing with it for over an hour and remember thinking well ****, there it is.

 

Thanks for the info. I have the rear fender off now and still can't see a 'loop'. Have the tank off too, I can see one of the plugs down the backbone neck , it's just an inch out of reach ! Tracing the wire bundle at the battery end of the backbone the wires seem to 'split' out from the loom and go different ways, they're out off the black wrapping, I can see the individual wire colours. I wonder if my model 03 has a different loom to other years ?...b.

 

Yep obviously your model year is different. I'm not splitting the plugs, I have a set of longer wiring already made up from the switches into plugs so I just need to locate the ones coming up the frame. Thanks for the help though...b.

 

The backbone is the large rectangular tube that runs from the neck to the swingarm. The back/bottom end of it is hurried behind the battery box at the bottom of the cavity under the seat. The service loop, if it hasn't been disturbed, is folded over itself and stuffed back up inside the backbone. It's completely sheathed in a black plastic sleeve. You should be able to see part of it peeking out the bottom end of the backbone or just folded into a mess under the seat.

Once the service loop is 'loose', you should be able to pull the wire harness up/forward out of the hole in the side of the neck. I had to push from the bottom while pulling from the top. I have a 99 and it was quite stiff. The connectors you need are maybe 12" inside the front half of the backbone.

If somebody has already tampered with yours, anything is possible. You may have to start disconnecting stuff at the bottom to get enough slack to expose the connectors.

Tie a strong string (nylon cord used for foundation layout worls good) around the bundle at the bottom before you pull too much up or you may lose some loose wires up in the backbone when pulling it back down.

 

Yeah maybe the 'loop' has been pushed back up the backbone. I'll look tomorrow. Going by my manual the 'loop' is supposed to be behind the rear fender on the belt side....mine's isn't.Thanks...b.

 

Forgot to add I have the battery out too...b.

 

I had to make a hook out of 1/16 welding rod to yank my loop out of the backbone.