CA77 Rear Tail Light Problelm Upon Re-assembly

quidger · Post by **quidger** » Sat Oct 27, 2012 10:30 am

'm about done re-assembling the 1968 Dream and I have one little snag that I hit. I would like to ask for some advice.

Electrical was 100% fine when I disassembled the bike. Upon reassembly all electrical is working well with the exception of everything related to the tail and brake light.

I had to do a lot of Bondo work on the top and near the brake light mounting holes area of the rear fender. I assume that the tail light uses the fender as a ground so I chipped off the Bondo to expose bare metal at the contact points where the brake light housing mounts to the fender. I sanded off all paint on the housing so that the two bare metals would have good contact area. Still no lighting for any of the rear light functions. I decided to try to circumvent the fender as a ground and directly ground the lamp. So I thought if I ran a ground wire directly from the tail light ground (copper wire ground that goes directly to the bulb) and clamped it to the motor fins that I should get a solid ground and thus, lights. No cigar. Should this maneuver have given me a good ground?

I am certain that the bulb itself is good.

I also checked and cleaned the connection where the wires are soldered to the bulb.

There were a few bare spots on the blue and the white wires that were in evidence when I took the bike apart. I electrical taped all of these area before I reassembled the bike. Wouldn't think that this would be an issue since the tail light functioned well prior to dis-assembly and prior to the electrical tape being applied.

I'm not sure how I might be able to test the connections with a multimeter.

So if you can give me some guidance and ideas on what you think the issue might be, it would be most appreciated.

Thanks

FluteTears · Post by **FluteTears** » Sat Oct 27, 2012 12:08 pm

Is the hot wire at the tail light getting 12v? when the key is on with headlight on
How about at the brake light switch? use a ohm meter on the switch press down the brake paddle and see if you have connection. With the key off.
if you don't have a wiring diagram get one on this site will help a lot.

Cheburashka · Post by **Cheburashka** » Sat Oct 27, 2012 1:03 pm

To back up what Flute Tears posted--are you sure the switch is in the right position? No tail light when you're only one click up from "off." It comes on with the headlight.

Hahnda · Post by **Hahnda** » Sat Oct 27, 2012 1:33 pm

Sometimes the contacts in the bulb holder have to be bent a bit or cleaned to make good contact on the bulb base.

quidger · Post by **quidger** » Sat Oct 27, 2012 2:39 pm

Progress! Brake light now working but no tail (with headlight on) or emergency light (last position on the switch).

Sanded all paint off bracket where not visible and I guess I finally got good enough contact for ground.

Still need to figure out why no tail light. First thought is that the #1 part of the two part bulb is fried.

Could it be anything else?

Thanks .

jensey · Post by **jensey** » Sun Oct 28, 2012 3:26 am

Hi,

Put the lights on, take a piece of wire, push one side to the negative of the battery, the other side to the metal base of the tail light inside (you have to remove the red plastic).

If it lights up, your problem is ground, if it doesn't light up, do the following test :

Take out the bulb, push the base of the bulb to the metal base of the lamp, take the wire, connect it to the positive side of the battery (be careful now) and connect the other side to the contact points of the bulb. If it lights up, it's the positive wire or wrong connections to the ignition key.

If both test fail, it's the bulb itself,

Jensen