1981 ct70 Headlight / stop light questions


New Member
Still trying to work through my wiring issues...

1. Should the headlight come on when the key is on but the engine is not running (high / low bulbs are good) ? The neutral light and tail light are working when the key is on and the motor is off.

2. Should the the stop / brake light work with the key on and the engine off?
Last edited:


Well-Known Member
I imagine if it's the same set up as the earlier models the headlights are AC powered so will not be on unless running. #2 should but the batteries are so undersized and or not fully charged that at times they seem lazy ie seem to react real slow.


New Member
1. The headlight runs off of the magneto directaly and only comes on when the engine is running. You do not even need the key to be on for the headlight to work. Thats how it is on my 1980 ct70 at least but I cant find a difference between the two in diagrams.

2. Yes, all the lights but the headlight run off of the battery. You NEED the battery in for the bike to start, it jumps the leads for the ignition to work and acts as a resistor for the electrial system. If its left out and the wires are jumped, you will blow fuses and very expensive headlights.