Battery draining when headlight on

All to do with wiring, charging or just trying to figure out whats gone wrong.

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CJF
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Re: Battery draining when headlight on

Post by CJF »

I would really appreciate your help with a diagram!!! THANKS
Chris

'76 TR500 Style Cafe
'75 T500 - Cafe Build Underway
'78 Honda CB 750 Super Sport
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jabcb
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Re: Battery draining when headlight on

Post by jabcb »

Starting with the GT500 wiring diagram at: http://www.ozebook.com/compendium/t500_ ... 00wire.jpg
I updated the GT500 diagram to better represent the actual setup:
gt500wire_upated.jpg
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BAS (Bike Acquisition Syndrome) - too many bikes but have room for more

Suzuki:
GT750 2x75
GT550 72 & 75
GT380 72
T500 69 project & 73 project
T350 69 & 71
Honda 85 CB650SC & 86 CB700SC
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jabcb
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Re: Battery draining when headlight on

Post by jabcb »

You can install a regulator/rectifier in two different ways.

This way continues to use the light switch to control alternator output:
gt500wire_upated_RR.jpg
This way bypasses the light switch to always provide full alternator output:
gt500wire_upated_RR_alt.jpg
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BAS (Bike Acquisition Syndrome) - too many bikes but have room for more

Suzuki:
GT750 2x75
GT550 72 & 75
GT380 72
T500 69 project & 73 project
T350 69 & 71
Honda 85 CB650SC & 86 CB700SC
09 Triumph Bonneville SE
CJF
To the on ramp
Posts: 306
Joined: Mon Dec 15, 2008 8:57 pm

Re: Battery draining when headlight on

Post by CJF »

Thanks for the diagrams!!! Really appreciate the help.

It looks like the first one is closest to the stock setup. Is there a benefit to the second approach vs the first? Also, it looks like there is a red/green going to the "new" box out section on both diagrams, but not hooked to anything. Where should that lead to?
Chris

'76 TR500 Style Cafe
'75 T500 - Cafe Build Underway
'78 Honda CB 750 Super Sport
User avatar
jabcb
Moto GP
Posts: 4241
Joined: Mon Dec 13, 2010 4:32 pm
Country: USA
Suzuki 2-Strokes: 69 T350 thru 75 GT750
Location: southwestern Pennsylvania

Re: Battery draining when headlight on

Post by jabcb »

The red/green wire that goes nowhere was for the old stock voltage regulator.
It doesn't connect to anything because you remove the old stock voltage regulator.

With the lights on, the second approach will produce a smidgen more alternator output.

With the lights off, the second approach will produce more excess alternator output. The regulator/rectifier converts that excess output to heat. So the regulator/ rectifier will get hotter with the second approach.

The Oregon regulator/rectifier that you use has a big heat sink, so you can use either approach.
BAS (Bike Acquisition Syndrome) - too many bikes but have room for more

Suzuki:
GT750 2x75
GT550 72 & 75
GT380 72
T500 69 project & 73 project
T350 69 & 71
Honda 85 CB650SC & 86 CB700SC
09 Triumph Bonneville SE
CJF
To the on ramp
Posts: 306
Joined: Mon Dec 15, 2008 8:57 pm

Re: Battery draining when headlight on

Post by CJF »

Sounds good. I will give it a try and let you know how it turns out. Thanks again!

PS: maybe we can get the moderators to make your diagrams a sticky...should help others looking to do the same on a GT500.
Chris

'76 TR500 Style Cafe
'75 T500 - Cafe Build Underway
'78 Honda CB 750 Super Sport
CJF
To the on ramp
Posts: 306
Joined: Mon Dec 15, 2008 8:57 pm

Re: Battery draining when headlight on

Post by CJF »

I took a ride yesterday after with the lights on the whole ride. I came back and the battery reading was 13.5v!!! I do believe the problem has FINALLY been fixed. Thanks again for your help.
Chris

'76 TR500 Style Cafe
'75 T500 - Cafe Build Underway
'78 Honda CB 750 Super Sport
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