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1981 CB750C Electrical Problems

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unTrevor

1981 CB750C Electrical Problems

I am working on a 1981 CB750C and came across an issue where the right front turn signal is on as a running light, but does not work as a blinker. The left side works properly. I have voltage going to the light on the right side, and when the blinker is engaged, there is the pulsing voltage expected. At the same time, the headlight stopped working, and I found there is no power going to the light. Has anyone come across this issue or know what could cause this?

TOOLS1

Re: 1981 CB750C Electrical Problems

Administrator

Sounds like a ground problem. Check the green ground wires. They are in the headlight, and run back down the frame.
TOOLS

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1976 CB 750-A X 2
1977 CB 750-A X 4
1977 CB 750-K
1976 CB 750 F
1981 CB 750
1966 Kawasaki SG 250
1981 KZ 750 LTD
1973 CB 350
1979 CM 185 Twinstar
1982 Honda XL 80
South of Eden (Kansas City MO)

sgtslag

Re: 1981 CB750C Electrical Problems

In reply to this post by unTrevor

Also check the #1157 bulb in the signal light: it is a dual-filament bulb, the turn signal filament may be burned out. I believe the headlight is a separate issue which just happened to fail at the same time. Cheers!

1979 CB750K (sold, 2012, but not forgotten)
1983 Kawasaki 440 LTD Belt Drive (sold, 2011)
1993 Kawasaki Voyager XII

unTrevor

Re: 1981 CB750C Electrical Problems

I am trying to figure out if this was a problem that just happened as we started working on the bike, or was it because we took the indicators off the tach/speedo assembly. I modified it to just have the speedo lights work and I capped off all the remaining wires for indicating turn signals, low oil, and neutral. Could any of those wires need to be jumped to allow any of this to work?

liam

Re: 1981 CB750C Electrical Problems

In reply to this post by unTrevor

i have and both of my lights dont work