electrical--lights on--key off

MKTLAWYER

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Supporting Member
I recently replaced my starter (again) and in doing so I broke the speedo plug wires. Have replaced that now as well (and new exhaust) and I had to replace the circuit breaker fuse under the seat that is green and looks like a blade fuse a (green 30amp). It already has replaced "circuit breaker" see here https://www.ebay.com/p/Big-Dog-Circuit-Breaker-Kit-HDW-2007-Pitbull-BDM/1923577546?iid=123782429576&rt=nc so I'm not sure the green circuit breaker should even be there but it will not get juice to start without it plugged in. Once plugged in, the headlight goes on and stays on with or without the key in ignition. Any ideas on what could be wrong and making headlight stay on or if the circuit breaker even belongs there? Replaced BDM EHC with Dead One ESC a year or so ago and all has been wonderful electrically until now. Thanks in advance!
 

bdm7250

Guru
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Pop your headlight out and see if you're grounding out in the bucket, if not the problem may be under the tank. (Chaffed wire I would suspect)
 

MKTLAWYER

Member
Supporting Member
Thank you! So if I understand, if the headlight is grounding out somewhere (anywhere), it will cause the light to stay on. Correct? Not like a typical short which in my mind would cause it to not work. Meaning it is a normally open circuit.
 

Sven

Well-Known Member
Not familiar with this bike bike to say it has a relay/starter/headlight design,but they use a relay for most headlights these days. In other words, the h/l draws a lot of current out of the battery if key was on and light came on as well. The trend was then to use a relay so when the bike started, the h/l was off for startup. But when the bike started, the relay would then magnetically hold the points so the wire of the h/l would now be on when running.

Say this bike comes with another relay besides the starter motor's relay. The points might be sticking closed/lost spring tension so no open circuit occurs/welded points to the h/l prong inside of the relay so the lights stay one when key is off. Can't be a short or the fuse would blow. Could be enough resistance [bdm's diagnosis] so no fuse blows, but has the headlight as a resistor so no fuse would blow this way either.
 

MKTLAWYER

Member
Supporting Member
Not familiar with this bike bike to say it has a relay/starter/headlight design,but they use a relay for most headlights these days. In other words, the h/l draws a lot of current out of the battery if key was on and light came on as well. The trend was then to use a relay so when the bike started, the h/l was off for startup. But when the bike started, the relay would then magnetically hold the points so the wire of the h/l would now be on when running.

Say this bike comes with another relay besides the starter motor's relay. The points might be sticking closed/lost spring tension so no open circuit occurs/welded points to the h/l prong inside of the relay so the lights stay one when key is off. Can't be a short or the fuse would blow. Could be enough resistance [bdm's diagnosis] so no fuse blows, but has the headlight as a resistor so no fuse would blow this way either.
Thank you for the thoughtful response. If I understand, check for a headlight relay and see if it is working?
 

Mr. Wright

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There is no headlight relay you can check. The problem is, if you have a short in a wire somewhere, it will cause all sorts of strange things. If you're still using the H4 headlight bulb, it causes a lot of heat and will melt the wires in the bucket. It's just a good place to start.
 

MKTLAWYER

Member
Supporting Member
Thank you for all your help and posts! I pulled headlight (have ceramic plug already) and checked it’s wires all the way (tank is off) to brain plug under seat. No shorts. Where should I look next? Would a short in any light’s wire potentially cause headlight to stay on or just headlight wire? I have an led light and there doesn’t appear to be anything wrong with it but the little black box it connects to in headlight bucket may be a little worn from possibly rubbing inside bucket but does not look major. But after all, headlight still works obviously. Ash colored dust in the bucket, not a lot, but some . . . Could short on any wire anywhere potentially cause headlight to stay on? If so, this will be a nightmare to figure out.
 
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