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Headlight Wiring

24673 Views 5 Replies 3 Participants Last post by  seruzawa
I hace a 2005 Honda Shadow 750 Spirit. I bought a bullit headlight. Need to know how to properly wire to exisitng harness. I was told green wire was negative but every time I try to ground it I blow a fuse. Any help would be appreciated. Aftermarket has only 2 wires where the factory has 3. I was also told aftermarket light was self grounding???
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I hace a 2005 Honda Shadow 750 Spirit. I bought a bullit headlight. Need to know how to properly wire to exisitng harness. I was told green wire was negative but every time I try to ground it I blow a fuse. Any help would be appreciated. Aftermarket has only 2 wires where the factory has 3. I was also told aftermarket light was self grounding???
"self grounding" means that your "third wire" is the headlight-housing itself - i.e. the ground. Not exactly the best way to do that, but it works (that's why the OEM used three wires).

Quick way to tell: switch on the bike, switch to low-beam - check with a multimeter set to DC-volt scale, any setting above 12v, red MM lead to the wire, black lead to the bike frame: the wire that has 12v goes to the low-beam on the new light.

Switch to high-beam - the wire that NOW has 12v goes to the high-beam. (or, if you have a "dual" setup, the one that was previously dead but now hot).

Ground the remaining (not hot) wire to the new headlight-housing. I would drill a small hole and attach with a crimped ring-connector using a machine-screw and locknut through the housing, or ground it under a mounting-bolt, ensuring that any paint or chrome was filed-off the contacting surface.

Good Luck.
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Green wire is only negative if you are wiring a house. Most m/c ground wires are black.
OH YEAH - all your connections should be crimped, with a CRIMPING TOOL instead of just mashin' them together with a rusty pair of pliers (parts stores have 'em for less than $10 - try to find one similar to this: IDEAL INDUSTRIES, INC. - Combination Crimp and Strip Tool ).

And don't just twist 'em together and tape 'em - unless you're good at soldering (or just like abusing yourself by having to do a job over and over and over again) and have a large-supply of heatshrink tubing. But, you likely wouldn't be seeking this sort of help if you knew how to do all that.

After each crimp, give the wire a good "tug" - actually try to pull it out. If you can dislodge it, better to find out your crimp-job was crap in the driveway than in a rainstorm on the side of the Freeway at Midnight.

If you like the belt-and-suspenders method of both a crimp AND a solder-joint (not really necessary, but... eh...) - Always ALWAYS Crimp FIRST - THEN solder the connection.

Solder will "cold flow", and if you solder a connector THEN crimp it, the heat/cool cycles WILL loosen the connection at odd times, and cause ghosts to haunt your electrical system.

Really pysses you off when that happens, believe-you-me.
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soldering doodah

OH YEAH - all your connections should be crimped, with a CRIMPING TOOL instead of just mashin' them together with a rusty pair of pliers (parts stores have 'em for less than $10 - try to find one similar to this: IDEAL INDUSTRIES, INC. - Combination Crimp and Strip Tool ).

And don't just twist 'em together and tape 'em - unless you're good at soldering (or just like abusing yourself by having to do a job over and over and over again) and have a large-supply of heatshrink tubing. But, you likely wouldn't be seeking this sort of help if you knew how to do all that.

After each crimp, give the wire a good "tug" - actually try to pull it out. If you can dislodge it, better to find out your crimp-job was crap in the driveway than in a rainstorm on the side of the Freeway at Midnight.

If you like the belt-and-suspenders method of both a crimp AND a solder-joint (not really necessary, but... eh...) - Always ALWAYS Crimp FIRST - THEN solder the connection.

Solder will "cold flow", and if you solder a connector THEN crimp it, the heat/cool cycles WILL loosen the connection at odd times, and cause ghosts to haunt your electrical system.

Really pysses you off when that happens, believe-you-me.
Correct soldering is not hard to do but has to be done properly. Few people are properly trained. The splice should be clean, fluxed and it has to get hot enough to wick the solder along the splice. It doesn't take that much solder. Proper aircraft and spacecraft soldering uses a minimum of solder.

The best splice to use on a bike is a "western union splice". In a pinch the western union splice will hold together quite well for a long time if tightly taped with electrical tape.
Western Union Splice

So, flux you if you can't take a joke.

I guess the custom chopper industry is fluxed.
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