Hey guys , so recently i did a head light conversion going from the dual 4'' lights to a single 5 3/4'' light using a Harley Light bucket Part #67700093B. Every thing went seamlessly. total plug and play set up . Dual lights utilized H13 bulbs. going to the Harley bucket, the harness changed to a h4 plug to mate up with the LED lights on the market. i used a Wasimic LED off of amazon for $50 i just cant muster spending the $325 price tag for the HD unit... well on 2 separate occasions in stop and go traffic (bike is ***** hot at this point) the high beam indicator kickes on and stays on (the light switch gear still works properly switching from high to low ) so i pull over to check for codes with the fp3 and i get a high low short fault. i reset the code and a few minutes later it'll kick back on. not till i pull over and have a few beer ( let the bike cool down) the fault goes away. ive checked all the connections , nothing is melted , no pinched wires. the only thing i can think of is the circuit board for the LED is acting screwy... any helpful incite would be great .

 

Model? Year? HD has been changing the wiring a lot.

 

2014 FXDF Dyna Fatbob, my bad.

 

Sorry. Missed it in the signature.. What can I say?? Getting old..

 

My guess would be that you don't have a good ground connection for the new headlight or the new plug is not wired right. Ground and one of the high / low beams is swapped.

 

It shorts when it is hot and the high-beam indicator is on, but all the lights still work normal. Is this correct?

Wiring problems typically are not thermal related, they are mechanical and you can usually duplicate the problem by manipulating the wiring. I am thinking that you have an intermittent thermal short that is probably indicating an internal cooling design flaw or thermal related component failure with the electronics.

When you get a chance, find some way to cool the unit down and see if it all starts working again...that pretty much narrows it down to a component or wiring...

 

I have a similar issue. I replaced my stock light with one of the non-HD LED daymakers. It was plug-n-play and I didn't have to do any rewiring. If I've been riding long enough for my bike to warm up and I hit the Bright switch then the little, red light on the speedometer will light up indicating an electrical issue. If I turn the bike off and back on the red light goes away. I checked the FP3 error log and same thing about High Low Short Fault.

I just attributed it to buying one of the cheap LED lights. Kind of a 'u get what u pay for' kind of thing. Since I know what it is and it doesn't seem to be hurting anything else, I didn't bother trying to find a fix.

When it first happened I did some web searches and other people have posted about the same thing. So this isn't really a lot of help to you on how to fix it, but rather just letting you know others have reported similar issues with the LED lights.

 

I'm not sure I'd call the design cheap.. (retired EE) I call it efficient. It's most likely that the high beam also powers the low beam as bright white LEDs are more expensive than adding a second filament to a bulb.. What they probably do is drive both the low beam and additional LEDs when using high beam. To do this they simply add a diode from the high beam to the low beam wire. When you flip the switch to high both low and high are powered.. I expect that the BCM senses voltage on the low beam wire and says the 2 are shorted. This is something the LED light designers missed so I guess it's more a minor design flaw.. The designers were planning on a simple toggle switch for control the beams which was pretty much the way before BCMs.

The fix is simple. Add another diode to the low beam so that the voltage don't bleed back to the BCM. Diode drops are less of an issue with LED lights as the usually have a power supply to keep current to the LED constant where the automotive 12 volts can recall be anywhere from about 9 to 15 volts..

 

Not sure what the filaments are like with the variations of bulbs you are showing in the pictures but, consider this. The bulbs themselves get hot and if the Hi-LO filaments short out with each other when they get hot it can f things up. I had changed out the big signals on my 93 Lowrider for the newer OEM bullet ones and when I did it I decided to wire my brake light to the running lamp filament, keeping the bright one for the signal so it would still flash if I was braking too. When I tested it I almost lost my mind. The brake light flashed with my right turn signal! No frigging way my wiring could do that I was sure. Finally after swapping the left and right bulbs and having the problem follow the bulb I figured it out. It ended up being that one of the BRAND NEW bulbs I bought for the signals had the two filaments dead shorted so when that side got a signal charge it shorted to the brake filament as well and made the brake light flash. So again especially if it happens when things get hot, maybe it's a bulb problem. Even brand new stuff can be bad. Hope this helps. Good luck, Billy

 

Exactly what i was thinking.. The company that sold me the light from Amazon is making me jump through hoops to get me a replacement.... they were trying to tell me that maybe the light was not compatible with my bike because of my dual light set up.. what a load of bull... Dyna's for the most part run the same main harness from what i gather... thanks for your insight Billy