83 CB1100F dim lights with key on

[mrmach5]

So all my lights are dim with just the key on (not running). 2 year old AGM battery, just load tested at the parts store, tested good and showed full charge. Checked all connections , grounds , corrosion , fuses etc. so where to go next ? Ignition switch, rectifier- regulator?

 

[Bo82CB]

You said "not running"!? Does bike start fine, how brite are the lights while bike is running?

 

[mrtwowheel]

That all sounds normal for these bikes. Turn the key on and the headlight is on. You need to be ready to start the bike as soon as you turn the key on. If you dally around and don't start the bike soon enough the headlight can zap the battery enough to not have enough voltage for the starter and ignition to work. The important points are, does the battery have enough voltage at rest (not running) should be over 12 volts. When the engine is running at 2-3K you should have more than 14 volts at the battery, 14.2 volts ideal. Over 15 volts there is a bad connection or bad regulator. This shows that you are charging the battery and that the rotor, stator and voltage regulator are working.

 

[mrtwowheel]

I've learned that it is always good to disassemble, fully disassemble, and clean the ignition switch on any bike.

 

[AutoMac]

My Honda is a 1976 machine and the riders manual says “ please note the machine will not be charging at idle speed .
So to check the state of charge going to the battery get someone to increase the revs and hold it at a constant rpm whilst you check the charge rate with a multi meter to the battery.

If enough charge is going to the battery suspect resistance in ether the ignition switch or light switch if fitted. Also check the earth strap on the machine is making a good contact .

 

[mrtwowheel]

Good point AutoMac, the starter switch also makes on/off connections for the lights. Worth cleaning connections in right and left controls.