76 GT500 Not Charging

[rbond]

If you want to keep everything as separate components like OEM, get a bridge rectifier with an 8amp-400volt rating at any electronics parts place( about $3.00). You may luck out with one that has male spade terminals to make connecting easier. Then get the Electrex regulator. I have a regulator built from a circuit I found online. The factory unit has very little in it and the circuit I found matches up perfectly. I have yet to test it as it is no fun taking the seat off! I need to see how much heat it throws off under riding conditions so I can make the needed method of housing it and cooling it before I post the circuit here like I did for the CDI. I really do not see any real problems with it, but I want to be sure I have a reliable part for GT500 owners and a alternative, made in USA (not counting the parts that make up the regulator) regulator. I have been running on this setup for two years now, I add a little distilled water once a month. This battery is at least 4 years old and still working fine.

[MonkeyWrenchCycles]

Would work just fine.

I thought the PEI box might be located under the seat & in front of the voltage regulator. That would have precluded mounting the Tympanium the way I did. Given your pic, that's obviously not the case.

Since the GT500 rectifier uses a latching connector, it will be less work to install a regulator/rectifier.

If you install the Tympanium the way I did, make sure you get a shorter bolt for the battery box. Since one of the bolts no longer secures the regulator, it long enough to penetrate the top of the battery.

Im kind of confused by the difference in the t500 wiring vs the gt500 wiring. Im attaching the wiring diagram for the charging system. Could you please help me with how to wire it up? If i am thinking right the green/white wire would hook to one of the yellows on the typanium the red would hook into the battery red wire, the yellow off the flywheel will go to the other yellow on the tympanium and the black would go to ground. Does that sound right? Would the red also have to splice into the yellow where the green wire from the coil connects to it? Thanks for all the help guys.



This is the modified diagram of how i thought it should be wired. Is this correct

[jabcb]

You are correct.

I updated your pic to make it a littler more clear:

gt500wire_tympanium.jpg

[MonkeyWrenchCycles]

Thanks!! Im gonna wire it up right now.

[MonkeyWrenchCycles]

It Lives!! Charges good again. Thanks for all the help everyone. It is much appreciated.

[CJF]

I've been following this thread because I'm also having some problems with my GT500 charging system. My rectifier and regulator have been swapped out for the Boyer Powerbox which has a reglator/rectifier and capacitor in one. It looks almost identical to tympanium in terms of wiring. It has two yellow wires going in and a red and black.

I have the yellow/green and red/green wires hooked to the two yellows, but not the green/white. I currently have the green/white going directly from the charge coil to the left hand switch (which is what I thought the wire diagram showed?)

My symptoms are that the volts are fine 13-15v when the light switch is off, but when the switch is on, it drops down to 7-9 volts and drains my battery (to the point that the battery was damaged). If I try combining the green/white and red/green to the yellow from the powerbox, should this eliminate my issue?

Also, the green/white needs to continue on thru the loom to the left hand switch. Do I need to splice off from the green/white, red/green and yellow connection and run the green/white to the left hand switch? Or, do I connect the green/white going to the left hand switch to the red coming out of the powerbox? This part of the diagram is a little confusing.

Help would be a appreciated!!! I already ordered a regulator/rectifier from oregon electronics thinking the powerbox was the problem and I may not have needed it!!

[jabcb]

Took a look at GT500 rectifiers on eBay.
They have only 3 wires going to the latching connector: R, Y/G & R/G

The T500 alternator has 3 wires: Y/G, R/G G/W

So the GT500 should have:
stator Y/G connects to rectifier Y/G
stator R/G connects to rectifier R/G (for charging coil)
stator G/W goes to light switch, switches to R/G, light switch R/G connects to rectifier R/G somewhere in wiring harness (for lighting coil)

Its likely that the PowerBox is ok. Which one do you have?
Looks like your lighting coil is not working. Possible causes: dirty/loose connector, light switch problem, bad lighting coil, or problem in wiring.

To check the stator:
1) check resistance between G/W & Y/G wires, should be about 1 ohm
2) check resistance between R/G & Y/G wires, should be about 1 ohm

With stator & PowerBox disconnected, check wiring:
1) check resistance between Y/G at connector for stator & Y/G at connector for rectifier, should be about 0 ohms
2) check resistance between R/G at connector for stator & R/G at connector for rectifier, should be about 0 ohms
2) with light switch on, check resistance between G/W at connector for stator & R/G at connector for rectifier, should be about 0 ohms

(You won't get a reading of 0 ohms. You'll get a reading near the multimeter's internal resistance. Touch the meter leads together to get the internal resistance.)

Combining the stator R/G & G/W, and then connecting directly to the PowerBox will bypass part of the wiring. If this bypasses the problem, then it will solve the problem.

[CJF]

Thanks for the advice. I checked all the settings you mentioned and they checked out ok. I ended up trying hooking up the green/white wire from the charge coil to the yellow on the powerbox and then the green/white from the left handlebar switch to the red wire on the powerbox. Problem solved I know have 13+ vbolts when the light switch is on and off. Really appreciate the help!

[citizenbanana]

This is how I mounted the Tympanium regulator/rectifier.
Its larger than the T500 regulator. I don't know where the GT500 PEI box is located -- you might need to mount the regulator/rectifier in a different way. Also, one of the bolts attaching the battery box will need to be replaced with a shorter bolt.
T500_tympanium.jpg

I modified this T500 wiring diagram to show the changes: http://www.ozebook.com/compendium/t500_ ... 00wire.jpg
Here is the modified diagram:
t500wire_tympanium.jpg

The Tympanium ground wire is brown as I've shown.
I used a green wire because its commonly available.
I soldered the 3 "Y" wire connections ( yellow to green & green, red to red & red, black to black & black).

The 4mm bullet connectors are available at http://www.vintageconnections.com/" onclick="window.open(this.href);return false;

Hi Jabcb,

Went with the tympanium. Wired it up per your diagram. just trying to test it out (have the harness out of the bike) have power going to the tympanium, ground is good. But no power coming out of either yellow wire. Lost all my lights etc. Did I get a bad unit?

[jabcb]

The yellow wires receive the AC output from the alternator. The yellow wires have no voltage when the motor is not running.

[joethebike]

I installed the Tympanium on my T350 and it works very well.