Headlamp doesn't work after rebuilding brakes

I'm proud to say I rebuilt the front brakes on my 1981 Seca 750 - thanks to Chacal and a bunch of forum members. Rebuilt. Calipers and master cylinder and new brake lines. The bike stops like it should and it's safe now. Thanks to all!

The problem now is the headlamp and auxiliary lights don't work. I'm not sure what to check. The bulb on the headlamp looks fine. My friend helped me replace the right handlebar switch assembly. The bike must have been dropped at some point and broke the threaded part where the brake cable connects to the assembly. My friend had to strip the switches and wires from the assembly that was on my bike before and connect them to the new (used) assembly. He checked the continuity on the switches, wires, etc before reinstalling.

I reconnected card all the wires and pushed them back into the headlamp.
No headlamp. The "head" indicator isn't displaying but it did display earlier when I partially hooked up the work to check the brakes on a test ride. The headlamp wasn't plugged in at that point.

Any suggestions?

Thx

JP

 

Anyone got any ideas?

Could it be incorrectly wired in the switch assembly?

Also, where might the fuse box be? I lifted the seat but don't see it?

Thx

 

If you did not see the fuse box under the seat then it's likely that a PO eliminated it.
The stock one looks like this (the smaller one is a new replacement that many of us have switched to):



I suggest that you get service manual, and become familliar with the wiring diagram. There is likely more wrong than just what was done at the headlight controls, but that is where you should start troubleshooting since the headlihgt was working before. Continuity dosen't mean a thing if the wires aren't connected to the correct circuits.

 

You are starting the bike before checking the headlight? Right? The headlight will not turn on until the engine has been running.

 

Thanks for the pic. I definitely don't have one right under the seat. I do have a Haynes manual but new to all this.

And I am starting the bike when checking the headlamp. That's what makes me think the switch assembly needs to be rewired. From what I have read, if the headlight is only on when the bike is running, the headlamp is wired into the starter switch.

I appreciate the input. And I will let you know what I come up with.

JP

 

Btw, I did find the registration stash spot on the underside if the seat with a previous po's old registration in a ziplock bag. I didn't that was up under there.

 

The little registration/insurance cert snap-on thingie is way cool. I use mine as intended.

You need your book.

The headlight is not wired to the starter switch; it's activated by the headlight relay upon it receiving a signal from the charging circuit that the bike is running. The relay is of the "latching' type; if the motor then stalls the lights will remain on until you switch the bike off again.

Oh, and beware the Haynes. It has bad info in it, like intake valve clearances for some models and jet positions in the Hitachi carbs. Remember Haynes is in the U.K. and they aren't as thorough in their research as they should be.

 

Update: headlamp mystery solved!

I looked for the fuse box under the seat and realized that the PO had wired fuses directly into specific wires. I found two wires that weren't connected and once I connected them, the headlight and auxiliary lamp worked. Glad I didn't start looking elsewhere first!

Thx

JP