free website stats program removed tach gauge and no passing lamp only works on one side | Harley Davidson Forums

removed tach gauge and no passing lamp only works on one side

My bike came with a tach, and I didn't care too much for the looks. Last week I decided to remove it. The previous owner installed the passing lamps and the tach. Don't know why but everything was spliced in-no wire harness for lights.:newsmile106: Basically I cut out all the splices from the tach installation and reconnected the wires to the passing lamps. Reconnected the battery and everything worked fine at first. The next day I was stopped at a stop light and noticed in my reflection on the car in front of me, that my left passing lamp and running light was out. I am an ok mechanic but a (EDIT)electrician. Is my lighting not properly grounded?

A Friendly Reminder - Harley Davidson Community

 
Last edited by a moderator:
Sounds like all those splices were wiring the left side driving light in "parallel" with the right driving light, and the left side running light in "parallel" with the right side running light. You will need an electrical schematic for your year make and model bike showing you the color codes so you do not cross wire to the signalling light circuitry or you could damage flasher or electronic switching circuits. "Parallel means connections branch together sharing a common voltage, rather than "series" like a daisy chained christmas tree light circuit where one break and everything is "open circuited" so the whole chain is dead.

Be sure, before rewiring anything, to face bike headlignt to a mirror or check in dimly lit garage and verify that all your signalling and flasher functions are okay BEFORE working on driving and running lights. Use your schematic and these attached simplified pix on the lamp wiring for front and rear. FYI, in the future before you modify something that is working, especially wiring, take pictures and carefully observe and label any wiring you separate (even though the wiring splices were cobby), they WERE working. All you need to do is disturb things as little as possible, use heat shrink tubing insulation, clean each wiring and splice one by one, soldering and then heatshrink the tubing to insulate...especially if you do not understand wiring. You will learn as you go...methodically and carefully and before you know it you will be able to troubleshoot and fix based on experience and online help here...the learning will come later, as you do each repair, test operation and move on to the next. Do not hack everything up and then try to piece and patch things back together...it just never works out if you are not familiar with electrical circuits and troubleshooting techniques using digital multimeter (DMM) and other tools...

Lights And Ignition

Wiringdiag.jpg


Hopefully you did nothing to affect the rear tail light wiring. If so, I have included a pix below to help you with this. Inside the tail light, there are modular plugs that are available to hook up auxiliary lighting such as fender tip lights on models that do not come with them installed. These plugs usually have dielectric grease in them to protect the contacts when not in use. Don't remove this grease before plugging in any lamp plugs.
On models not having fender tip lights, you'll find that the #45 receptacle will be open and the HD lighting will contain the necessary plug to just plug in here and mount the light.
These connections are located behind the reflector.

Taillightsockets.png
 
Last edited:
Thanks HD74FAN, I am going to give it a go tomorrow. I have borrowed a wiring schematic for the same year as my Fatboy, and in the process of getting original instructions for the passing lamps from my local HD dealer. These and the information and tips you provided should help me a lot. Thanks again!
 
Glad you got it all sorted...just take things slow and easy, plan things over a 2 or 3 day repair window and this do it yourself stuff gets better and better. Harleys are rugged and kinda like tractors in a good way, with a kind of bare knuckles design...! :D
 
Back
Top