Headlight dims w/turn signal - Battery Issues (Yes I searched)

[cableguy]

Electrical troubleshooting isn't my strongest area, but I can follow a plan and use a multimeter. That being said, I'm at a loss for where to start looking for this issue, if it even is an issue, and maybe I should be looking elsewhere.

I'm thinking I may need a new battery, although it was brand new 2 years ago, and stored on a tender last winter and the one before. Last season I thoroughly checked/repaired all of the wiring connections, and followed the stator papers to check the stator (good, and did the direct-wire to R/R), and the R/R. The R/R was bad, so I replaced it with a Honda unit.

What's happening is my battery intermittently dies. By that I mean some days it starts right up the day after a ride, sometimes not. My riding hours are usually consistent, start when it's light, come back in the dark. What I notice is that my headlight dims maybe 30% on braking, and also dims with the turn signal. Last night the instrument lighting was also dimming.

Before I tear it all apart again, can someone please help me form a plan of attack? Thanks in advance

[duaneage]

Get a volt meter and check the running voltage at the fuses. The feed on the main should be the highest, it should be 13.6 or greater at 2000RPM
Then move to the fuses for the lights and start going through connectors, switches, etc until you find the place it drops. Leave the - black lead on the meter connected to the frame, not the battery.
You probably have a dirty ignition switch but rather than guess take the time to test the voltage at different points until you find it. Too many times we throw parts at a problem without verifying what the issue is. I find cleaning switches once a year in the spring with contact cleaner prevents problems and gives me full voltage everywhere.

[cableguy]

Can you think of a reason why the headlight would dim in coincidence with the turn signal? Does everything go through the ignition switch from the fuse box? I will certainly refer to diagram but I'd like to get my head around this today so I can attack it with intelligence when I get home.

[duaneage]

Can you think of a reason why the headlight would dim in coincidence with the turn signal? Does everything go through the ignition switch from the fuse box? I will certainly refer to diagram but I'd like to get my head around this today so I can attack it with intelligence when I get home.

Short answer is yes, it goes through the same circuit in the beginning, and everything goes through the ignition switch. These are 30 year old bikes, wonderful machines but a lot of road gunk makes it's way into switches. The handlebar switches are not sealed well and benefit from cleaning with electrical contact spray like DeOxit or eq,

Ground the meter to the engine and measure the resistance in ohms to the frame, the negative battery terminal, the RR ground, the back of the bike where the turn signals are. It should all be less than 1 ohm.

[cableguy]

Thanks for the guidance. I swear I develop ADD when it comes to electricals. Basically point me in a direction and I can follow a path but I can ever find the darn path!