×
Pictures Posting Not Working (12 Jun 2023)
Picture uploads is again unavailable. We are working on the problem. Thanks for your patience.
Makotosun
1972 Yamaha CT2 175 rebuild update - Battery drain
- 78dave
-
Topic Author
- Away
- Senior Member
-
- Posts: 43
- Likes received: 13
1972 Yamaha CT2 175 rebuild update - Battery drain was created by 78dave
First thanks to all for your input. I have the bike up and running after a complete rebuild and it sounds really good so that is a positive. I noticed back a while that my battery (yes I know I don't need it) would not be at 6V after being in the bike. I have been chasing the neutral light that does not work. New bulb and it lights, but not getting power up front through the brown wire. The light blue wire from the switch is indeed grounding out in neutral, but no light on tach. I would assume I need a battery to get that light to lite. Thought on lost power up front and battery drain. All lights are removed and are brand new as they were removed back in the 70's and stored - will likely be selling that set off soon. I appreciate the help
04 Mar 2026 06:30
#1
Please Log in or Create an account to join the conversation.
- Gr8uncleal
-
- Offline
- Site Supporter
-
- Posts: 4820
- Likes received: 2621
Replied by Gr8uncleal on topic 1972 Yamaha CT2 175 rebuild update - Battery drain
Are the other items (assuming that they're fitted!) that take power from the battery working ok? We're talking horn, indicators and rear light here. If they aren't, it could be the main switch, or maybe even the fuse.
Dodgy charging coil or rectifier could be the cause of the battery not charging when engine running.
Dodgy charging coil or rectifier could be the cause of the battery not charging when engine running.
04 Mar 2026 06:53
#2
Please Log in or Create an account to join the conversation.
- 78dave
-
Topic Author
- Away
- Senior Member
-
- Posts: 43
- Likes received: 13
Replied by 78dave on topic 1972 Yamaha CT2 175 rebuild update - Battery drain
So nothing on the bike now - no horn, switch, tail or side lights. Wiring is still intact. I will check to see if I am charging today. Battery was low last night which caught my attention. Might do an amp test to see if it is leaking. I cleaned the main switch and it looked pretty good. My mind is always drawn to red + and Black - but it is the brown wire carrying power up front.
04 Mar 2026 06:58
#3
Please Log in or Create an account to join the conversation.
- 78dave
-
Topic Author
- Away
- Senior Member
-
- Posts: 43
- Likes received: 13
Replied by 78dave on topic 1972 Yamaha CT2 175 rebuild update - Battery drain
Ok I tested the resistance across all the contacts coming from the switch using the switch diagram in the service manual. I do not have continuity across the red and brown wire and that would tell me why no power is going to the front of the bike where I need the brown wire for power. Thoughts?
04 Mar 2026 08:52
#4
Please Log in or Create an account to join the conversation.
- Gr8uncleal
-
- Offline
- Site Supporter
-
- Posts: 4820
- Likes received: 2621
Replied by Gr8uncleal on topic 1972 Yamaha CT2 175 rebuild update - Battery drain
Did you mean continuity as opposed to resistance?
Sorry if I'm teaching granny............!
Sorry if I'm teaching granny............!
04 Mar 2026 09:04
#5
Please Log in or Create an account to join the conversation.
Moderators: yamadmin, Makotosun, DEET, Vinnie, James Hart
