Battery draining when headlight on

[rbond]

As a bit of advice, after you solder your wires to the coil(s) put a liberal covering of epoxy on the solder joints, or you WILL be re-soldering it again (no pun) shortly from vibration. I learned this the hard way when I replaced both ignition coils on my GT500. I got to the point of 5 minutes to get everything off to get to the stator......

[CJF]

Take a look at this, the coil is definitely toast. The insulators holding the coil winding in place are missing and it was flopping around inside the mount. It's a mess!



I picked up two new coils and some wiring that matches the OEM colors. I epoxyed the ignition coil wire solder points per rbond's advice. This is a pic of the rewire job underway. I had to stop midway last night, but will pick it back up in a few days and finish the job.


One thing that did disturbed me a bit is that I saw a small amount of oil collecting around the crank seal. I just had this crank rebuilt a year ago. Is this small amount of seepage ok? Not sure if you can see it, but there is a little around the outside diameter of the seal and a tiny bit that pooled at the bottom of the crank case under the stator plate.

[rbond]

If the leak is on the outside edge, you might replace the seal, and if you did not the first time, try putting a light coating of Hylomar sealant around the outer edge of the seal. If this works, it only costs a seal, at least you tried something reasonable, rather than pulling the motor and splitting the cases.

[CJF]

I realized since my last post that it may be coming from the outer edge of the bearing where it meets the cases. I guess this means there is a small amount of oil getting past the o-ring between the case and bearing.

[CJF]

I wired in the two new lighting coils and now have 14-16 ac volts at each coil. I went for a short ride with the lights on and checked the battery when i returned and it was 13v. I think it is fixed at this point, but will need to go for a longer ride to say for sure. The ride i took was only about 20 minutes....too cold out there!!!

[jabcb]

Great.

The Oregon regulator/rectfier does a much better job of controlling voltage that the stock regulator did. You can switch to a maintenance free or AGM battery if you want.

The old T-series bikes didn't do a very good job of controlling voltages. I've measured 16+ volts, which was considered ok. Not a big deal to add water to make up for what was boiled off by this high voltage. But it is a shame that this resulted in so many otherwise-very-nice exhausts having acid stains.

Maximum charging voltage for AGM batteries is no more than 15 volts. (14.7 is a better maximum & is the maximum specified for some batteries.) Modern regulator/rectifiers meed this requirement.

The Oregon unit you got is a good. I'm using the Tympanium regulator/rectifier on my T500. It doesn't have the current capacity of the Oregon's, but its fine for the T500/GT500 and its cheaper & easier to mount.

[CJF]

Thanks, I really appreciate your help. I like the Oregon products. I have one of his regulators on my CB750 as well and it has been working great for years. BTW...I have Shorai Lithium battery on the bike now. Those things are pretty amazing in terms of the size and weight difference. I'm hoping all is well with this fix and the whole system is maintenance free for a while.

[CJF]

Just took the bike out for a long ride and guess what.......the damn battery drained down again. I think it could be a bad ground somewhere. More work to do...............

[H2RICK]

Chris, why not rig up a temporary voltmeter and temporary ammeter ??
That should give you a better idea of where your problem lies.

[CJF]

I did some work today to find out what is causing the issue. I took a precautionary step to add a 14 guage ground wire off the battery to a fresh/clean spot on the frame...replacing an 18ga wire. I also think I could have narrowed things down to problem with the ignition switch, but not 100% sure. I tested volts from the + battery post to the orange wire coming from the ignition switch. When the switch is off, I get around 12.8v. When I switch the key on, it drops to zero. I should be getting 12+ volts on the orange wire shouldn't I???

[jabcb]

Take a look at the wiring diagrams:
http://www.ozebook.com/compendium/t500_ ... 00wire.jpg
http://www.ozebook.com/compendium/t500_ ... 00wire.jpg

The orange wire should be the hot wire from the ignition switch to the rest of the bike.

With switch in off position, its isolated from +battery by switch, and connected to ground thru bike wiring. So you get about 12V in your test.

With switch in on position, its connected to +battery by switch & red wire. So you get a low reading close to 0V.

So the readings you took look ok. (Am not 100% sure because I haven't seen the complete wiring diagram for the GT500.)

Its worth rechecking the alternator resistances & voltages. Perhaps one of your connections came loose from the engine vibration. Or a wire shorted out.

Also check voltage at battery with bike running + lights off, and bike running & lights on.

[CJF]

I'll double check the volts with engine on, lights on/off. I did this check yesterday, but can't remember what it was. As far as the ignition switch, I get zero volts on the red and orange when I switch the key to the on position. That led me to believe there was an issue with the switch that in some way was causing the battery to run down. Not sure how I got to that conclusion....more hoping than knowing.

Also, I did a bunch of other checks. I checked vac from the stators and got 50-52vac from each of the wires off the stators. I got 1.4ohm between the stator wires. I also checked stator wires to ground and got around 1425 then dropped to around 900-1000 (I had the meter set on 2000K because there was no reading on any other settings). Not sure about this reading, but I think the rest are correct.












The other thing I noticed that seemed weird was that the volts were higher at idle than higher revs. At idle with lights off, I was getting around 14v and at higher revs around 2,500 it dropped to around 13.2. I would have tought it would be the other way around with the volt reading.

[jabcb]

50-52VAC & 1.4 ohms are good. You solved the problem that was giving you those low AC voltages.

Do you still have the stock voltage regulator hooked up?

[CJF]

I do think the lighting coils needed to be replaced given the condition they were in, so that wasn't wasted money or effort.

I just double checked the volts with the engine running. With lights off, I had 14volts off the battery. With lights on, I had 13.5volts. I also double checked with reving up the engine between 2k and 4k and the volts did rise back up to 13.8-14volts. It seems like that is good and where it should be.

I have the oregon electrics regulator/recitifier on the bike.

Maybe I messed up the way the lighting coils are hooked up to the reg/rec unit? I was looking again at the diagram you made up in the other thread. My setup seems more complicated with additional wires allowing for the handlebar switch hookup in the existing loom.

Here is how I have it set up:
red/green and yellow/green from coil to yellow on reg/rec.
green/white from coil, green/white to handlebar switch, red/green to handlebar switch all to the other yellow wire on reg/rec
red from reg/rec to pos on battery
black from reg/rec to neg on battery
Red off pos battery to fuse and then to ignition switch
Black off neg battery to frame ground

Does this look right?

[jabcb]

You have it wired up so that you are using only one of the two coils.
You also bypassed the handlebar switch, so you only needed to connect one of the three wires.

I'll make a diagram for the GT500 so you can see how to wire it up.
This will give you more alternator output & should fix the problem with the battery drain.