Headlight testing?

[kenkah]

I was wondering if there was a way to do a bench test on the headlight? I have CA77 Dream and I'm not sure if I have wire issue or if the headlight is shot. Thanks.

[rzgkane]

I was wondering if there was a way to do a bench test on the headlight? I have CA77 Dream and I'm not sure if I have wire issue or if the headlight is shot. Thanks.

Just put 12V to each wire (blue and red for high and low if it's like my '65 CA77) and ground the green wire. If you have light, you have a good bulb.

Remember, though, that when installed, the headlight grounds to the frame through that screw below the headlight. If you just have the light loose and not mounted, it will not be grounded and will not illuminate.

[kenkah]

Thanks for the reply. Gonna test it out this weekend and see where I'm at with it. hopefully my other parts come today and I can work on my rear wheel and hub.

[kenkah]

I was able to test the light and the bulb works. now to find why its not working when on the bike. Thanks for the help.

[rzgkane]

First, with the key in the #3 position, check for power going TO the headlight dimmer switch. The dimmer switch wiring will usually be encased in a blue sheathing. If no power there, you probably have a bad ignition switch. Unlikely.

If you have power going TO the switch it is now time to check power coming FROM the switch to the headlight. Check for power at the blue wire and then the red wire at various dimmer switch settings. If no power there, you have a dimmer switch issue. You have to take it apart and clean the contacts inside. If you have power there, and a good headlight, I would check for proper grounding of the headlight's green wire.

DO NOT try to do this dimmer switch cleaning with the switch on the bike. It is darn near impossible to get the switch back together unless you have it on a bench. CAUTION: Take the switch apart in a controlled setting so the detent ball bearing and spring that are inside do not fall to the floor and head for Japan.

When removing the switch and pulling its wires through the handlebars, first tie a piece of mechanic's wire to the ends of the wires so you are pulling the mechanic's wire through the handlebars as you are pulling the switch out. That way, when you are ready to reassemble, you just tie the terminal ends of the switch wiring back to the mechanic's wire and pull it right back through the other way.

Good luck. That circuit is very easy to diagnose.

I was able to test the light and the bulb works. now to find why its not working when on the bike. Thanks for the help.[/quote

[rzgkane]

First, with the key in the #3 position, check for power going TO the headlight dimmer switch. The dimmer switch wiring will usually be encased in a blue sheathing. If no power there, you probably have a bad ignition switch. Unlikely.

If you have power going TO the switch, it is now time to check power coming out FROM the switch to the headlight. Check for power at the blue wire and then the red wire at various dimmer switch settings. If no power there, you have a dimmer switch issue. You have to take it apart and clean the contacts inside. If you have power there, and a good headlight, I would check for proper grounding of the headlight's green wire.

DO NOT try to do this dimmer switch cleaning with the switch on the bike. It is darn near impossible to get the switch back together unless you have it on a bench (or you are sitting on the carpeted floor Indian style like I did). CAUTION: Take the switch apart in a controlled setting so the detent ball bearing and spring that are inside do not fall to the floor and head for Japan.

When removing the switch and pulling its wires through the handlebars, first tie a piece of mechanic's wire to the ends of the wires so you are pulling the mechanic's wire through the handlebars as you are pulling the switch out. That way, when you are ready to reassemble, you just tie the terminal ends of the switch wiring back to the mechanic's wire and pull it right back through the other way.

Good luck. That circuit is very easy to diagnose.

I was able to test the light and the bulb works. now to find why its not working when on the bike. Thanks for the help.[/quote