Good evening. Long time, no post. I have not been on here in years, since I owned that '77 super glide that was cobbled together. I have not owned a bike in a few years, until a few nights ago when I picked up a 1998 Dyna from a local guy. Bike is in decent shape, got it at a good price. I bought it after work and was tired / hungry and checked the major stuff before buying, but I did not do a walk around on the lights.

After getting home I realized the horn does not work, and the rear turn signals do not work. The Headlight and front turn signals are after market LED crap, and I think the previous owner hacked some of the wiring.

Thus far I used the multi meter ohm function to confirm that all 4 "resetable" fuses showed continuity, all four fuse housings show 12v. I disconnected the wire harness that feeds the tail light and rear turn signals and did get 12v at a few of the terminals, but I have been unable to get 12v at either light bulb socket on the rear signals. If I actuate the turn signals, the front signals to dont blink, instead they cycle through 3 different color variations that the LED aftermarket lights can do.

I believe I read somewhere that the rear turn signals and horn were both on the same circuit, or perhaps thats newer bikes?

Any sage input on how to go about diagnosing my issue? Thanks

 

Are the indicators LED? That'll stop them flashing if you don't have load equalizers or a Badlands unit fitted.

Horn runs off the left turn signal feed and fuse but it tees off the front indicator, before the feed heads to the control signal unit.

Message me your email address and I'll send you scans of a coloured wiring diagram.

 

Repair manuals here:
https://www.carlsalter.com/harley-service-manuals.asp

 

If it's wired like my 94 FXSTC, all the wiring from the bars goes to 2 molex connectors on the back bone under the tanks.
You can access them by removing the right tank.
From there it branches off to the other components.
As you've noted the horn and blinkers are on the same self resetting fuse.
Everything going to the rear fender area is on another connector under the seat.
Start tracing wires back to the connectors under the tank.
I'd remove the multi color LEDs, they sound like gimmicky junk, and find the Load Equalizers.
The TSM won't permit the lights to blink if it doesn't see enough load.

 

Cannot not speak to LED's and all the havoc they may cause but when the horn does not work, 9 out of 10 times it is the ground to the horn. It either falls off or breaks off behind the horn itself, good luck.

 

Thanks for the responses. I am going to slide into the garage for a bit before work this morning and do a few tests that I brain stormed up while lying in bed. Go from there.

Cheers

 

The left grip housing is where 12v for horn comes from...and Left signal as well, front and rear tho...so...probably 2 separate problems my guess!!
Run a wire direct from battery + to horn wire flag... if no beep, it aint grounded or horn broke...I'm gonna go with bad ground, for rear signals only. Wire from neg. of battery or good chassis ground to signal housing??? I would need to Look into socket to get more...
I need to look up if the signal wire are still Brown and Purple later production MoCo

 

Firstly thank you Spanners for emailing me the two wiring diagrams. I know a bit of 12v electrical, but unfortunately my diagram reading skills are lacking. A few hours in the garage after work yielded nothing of value.

I used to a test light to confirm voltage at all four fuses

I confirmed no voltage at either rear turn signal

I confirmed that the female harness which feeds the tail light and both rear turn signals does not have power at the pins corresponding to the purple wires

I followed spanners advice, and looked into the front turn signals. I ended up cutting off the shrink tubing to see what exactly was done up by the bars. The three appropriate wires were all connected and done pretty well by who ever wired it, so now that will have to be re-insulated. I was thinking that maybe the front signals and the rear signals joined up there, as the fronts are supposed to supply power to the rear. The wire harness for the front signals feeds into the frame of the bike then heads down to the seat area. Its too difficult for me to make heads or tails of the various harnesses present in the seat area, so I am thinking tomorrow I will pull the battery out to try and get a better visual of everything in there, and identify exactly where the front signal power wire and rear signal should meet.

Pretty discouraged. The last thing I need is another project, and more stress.

 

Youre thinking a bad ground is the culprit for the rear signals not working?

 

For anyone following along. I have been at a dead end with these lights. Nothing seemingly is wrong with the wiring.

Well, thats because there wasn't. Right as i was thinking how to ghetto rig the tail lights on I decided to push the turn signal button. Behold, the tail light turns on. So either I remove the LED front signals as was suggested, or leave everything and just pre set the rear signals on and use hand signals for turns. For now I think I was cycle the rear lights on so I can ride the damn bike. Dad wants to go fishing anyway so I'll ride over there.