Bike is a 2007 FLHTCU with 35,xxx miles on it. No modifications besides new bars (no wire extension) and a replacement horn. This problem will be the death of me, it's been a long process and I feel like I am going nowhere.

First things first, on a great ride, notice turn signals don't work, horn doesn't work and cruise control won't work. Speedometer still working at this point. Fuses blow, replace, last awhile and then blow again.

Long story short, discovered that everyone usually points to VSS as the problem, switched it out, nothing has changed and now my speedometer isn't picking up speed. It still goes from 120 to 0 when I put it in DIAG but won't register when I'm riding. Odometer and light still working though. Fuses still lasting for a slight bit and then blowing. I pulled the fairing and looked at the harness/plug for the speedometer, everything checked out with a power probe. I put new bars on the bike after all of these issues started, I didn't like the bars on the bike and decided that if I was going to tear into it to trouble shoot my problem, I might as well switch the bars out. The bars that were on were outrageously tall ape hangers so I did not need to extend the wiring or anything like that.

I want to warn you, I know very little about electrical. I just now decided to check the wiring. (I know! I should have done that first but I'm lost when it comes to electricity.)

Without further to do, when I checked the wiring going to the VSS, I have a ground, a no-reading (read that that can be the "sending" wire) and 4.5vs on the "positive?" I am very confused, did I just find my problem, or is the system only supposed to get 4.5v at the VSS. I have the Clymer manual for my bike but when it comes to the nitty gritty like voltage values, it leaves a lot to be desired.

To compound the frustration, I see on this thread that this problem is somewhat common however it seems like no one has be able to reply with a fix that works on my bike. I'm hoping that I am not supposed to be getting 4.5v at the VSS and I just found my problem.

Any help would be greatly appreciated! Thank you in advance.

 

What kind of replacement horn?
Reason: some horns are high load and require a relay or the horn switch can become damaged and blow a fuse when used.
When you state "Odometer and light still working".
Does that mean that odometer mileage is recording the exact distance traveled?
To clarify: if you travel 2 miles, the odometer will record that 2 miles have been traveled.
The vehicle speed sensor uses 5 volts as the trigger voltage in some model years.
Many wire problems on a FLHTCU are related to wire loom at neck frame. Most times a short will be discovered when bars are turned to one side.
Another common spot for a short circuit might be underside of rear fender if it was lowered at rear and tire scrubbed against wire loom on underside top of rear fender.
Just because the handlebar wiring was done before does not mean it is OK.
You know what fuse blew so you know the circuit that requires review.

 

 

IM has a good point …. the horn might be drawing to much power and blowing the ACC fuse. Try disconnecting the horn and see if the fuse blows. On many bikes, the ACC fuse will power the Speedometer, turn signals, horn, & brake light. Without looking at a wiring diagram for your bike, I can't be sure if the Cruise is also on that fuse.

 

 

Same issue on my 2001 Heritage. I'll be interested to see what you find. Thanks!

 

 

I read this quick, so probaly wrong. My 07, and I don't think anything unique to 07, had intermittent lights, from bad plug under fairing. Dealer tywrapped under warranty. I never made it back to have the plug replaced.

 

Unlikely the problem is your VSS. You noted the bars were changed out. So, specifically ... what fuse or fuses are blowing?

 

I'll bet you've got a pinched wire in the left side switchpack, causing a short.

GM