Badbmwbrad
03-09-2013, 03:20 PM
I scored a rear tail light for my 1985 Honda ATC 110. It connected up OK but no light.
After removing the light bulb, it appears the lighting filament has failed. No problem. It's a conventional Stanley 12V 3.4W lamp.
I figured while I had the wire connectors and lamp socket accessible, I'd clean it with electrical contact cleaner then measure voltage with a Fluke multi-meter.
With the voltmeter to DC volts, I started the engine and placed the headlamp switch to on position... but no DC voltage measured at the tail lamp socket is indicated on my Fluke meter. WTF?
The tail light wires were disconnected from the ATC wiring harness and the Fluke was connected directly to the bike's wiring harness... but no DC voltage is indicated.
After some head scratching and wiggling the wires for a while, I set the Fluke multi-meter on AC volts and viola! The voltmeter indicates about 8.5 VAC at idle and a little more than 14 VAC at higher engine RPM.
Checking an ATC wiring diagram available at 3WW, I do not see any diodes or capacitors in the lighting circuit.
Please peer-check my determination that this bike's lighting system operates on alternating-polarity voltage.
PS I connected a spare lamp in the tail lamp socket and it does light up but not sure what wattage it is (yet).
The
After removing the light bulb, it appears the lighting filament has failed. No problem. It's a conventional Stanley 12V 3.4W lamp.
I figured while I had the wire connectors and lamp socket accessible, I'd clean it with electrical contact cleaner then measure voltage with a Fluke multi-meter.
With the voltmeter to DC volts, I started the engine and placed the headlamp switch to on position... but no DC voltage measured at the tail lamp socket is indicated on my Fluke meter. WTF?
The tail light wires were disconnected from the ATC wiring harness and the Fluke was connected directly to the bike's wiring harness... but no DC voltage is indicated.
After some head scratching and wiggling the wires for a while, I set the Fluke multi-meter on AC volts and viola! The voltmeter indicates about 8.5 VAC at idle and a little more than 14 VAC at higher engine RPM.
Checking an ATC wiring diagram available at 3WW, I do not see any diodes or capacitors in the lighting circuit.
Please peer-check my determination that this bike's lighting system operates on alternating-polarity voltage.
PS I connected a spare lamp in the tail lamp socket and it does light up but not sure what wattage it is (yet).
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