T500L not charging enough when lights on

[karl pa]

Definitely something wrong, it is just a matter now of finding where the problem lies. Unfortunately it can try your patience at times.

[malky]

I don't seem to have a white/green lead coming from my alternator just red/green and yellow/green - I'll double check it when I get in the garage

[karl pa]

The Green/White wire should be in the 4 wire plug with black and white (points) and blue (neutral switch)

[jabcb]

The R/G & Y/G alternator wires connect directly to the rectifier — they have bullet connectors.
The G/W alternator wire goes to the left handlebar controls. As Karl said, it’s included in the 4-wire connector.

When checking resistance of the alternator, check the R/G & Y/G wires at the bullet connectors, and the G/W wire at the 4-wire connector.

To check AC voltage when running, you need to connect up the 4-wire connector. The G/W wire changes to an R/G wire at the left handlebar switch.
So check the Y/G wire & two R/G wires that connect to the rectifier.

[malky]

Thanks guys I have plenty of info and things to check now ' one other thing I have a spare regulator but it's off a GT500 and only has an earth lead and one red/green lead - it doesn't have the orange wire that goes to the flasher unit ,will this work on the T500 as I can't see any reason for it to be connected to the flasher unit ?

[jabcb]

The stock voltage regulator for the T500 & GT500 are essentially the same. They keep the max voltage from exceeding 16V.

For the T500, Suzuki added a voltage regulator to a wiring layout that didn’t have one. They put it between the existing wiring & the flasher.
The GT500 has PEI instead of a points ignition, so it was a fresh design that included a voltage regulator.

16V is way too much for your AGM battery. But this isn’t an issue while you are diagnosing the electrical system & have a max of 13V.
After you figure out the problem & do the repair, it would be best to switch to a modern rectifier/regulator.

[malky]

The stock voltage regulator for the T500 & GT500 are essentially the same. They keep the max voltage from exceeding 16V.

For the T500, Suzuki added a voltage regulator to a wiring layout that didn’t have one. They put it between the existing wiring & the flasher.
The GT500 has PEI instead of a points ignition, so it was a fresh design that included a voltage regulator.

16V is way too much for your AGM battery. But this isn’t an issue while you are diagnosing the electrical system & have a max of 13V.
After you figure out the problem & do the repair, it would be best to switch to a modern rectifier/regulator.

Cheers - as a matter of interest why was it connected to the flasher unit wiring ?

[jabcb]

Took a closer look at the wiring diagrams.

The T500 voltage regulator has 3 electrical connections: AC, switched DC+, and ground.
The turn signal relay uses switched DC+. The voltage regulator was inserted between the turn signal & its switched DC+.

The GT500 has 2 electrical connections: AC & ground.
The design makes an assumption about the rectifier’s performance in converting AC to DC.
These bikes were engineered & built to cost -- this was a modest cost savings.

[malky]

Took a closer look at the wiring diagrams.

The T500 voltage regulator has 3 electrical connections: AC, switched DC+, and ground.
The turn signal relay uses switched DC+. The voltage regulator was inserted between the turn signal & its switched DC+.

The GT500 has 2 electrical connections: AC & ground.
The design makes an assumption about the rectifier’s performance in converting AC to DC.
These bikes were engineered & built to cost -- this was a modest cost savings.

Thanks , so will it be OK to use the GT one on the T500 and just connect the earth and red/green wires ?

[jabcb]

Should be fine with the stock battery.

The stock battery responds to the 16V by boiling off some of the water -- that's why you have to add water so often. And make sure the battery vent tube is connected. Most of the original exhaust pipes has chrome damaged by the venting battery.

[malky]

Right swapped the regulator with the Gt one and its better but still struggling to hit 13v lights on or off - I can't seem to get any reading on the output leads either the multimeter black probe to earth I assume I should be on the 200v AC setting with the red probe where it is here or am I doing something wrong ?

[Alan H]

If you're testing DC - or a battery circuit - you need to be on 20v DC (or 3 clicks to the left on the pic).
AC, or alternating current, go to the lowest setting ~ which on your tester is 200 (2 clicks right).
I would suggest you get a 'proper' self ranging tester similar to ebay item 325256368293, or even better, a Fluke. Easier to use and more accurate.

[malky]

Cheers Alan I was on the right setting then but why couldn't I get a reading with the engine running - I did an ohms test static and got an open circuit result so assume the windings are OK

[jabcb]

Not sure what you are asking.

Multimeter leads are correct for DC & AC voltage readings. For DC test use 20V-. For AC test use 200V~.

To check the alternator AC voltage without load:
1) take a close look at this diagram: download/file.php?id=690
2) disconnect the voltage regulator
3) disconnect the Y/G, R/G & R/G wires connecting the the rectifier
4) AC voltage test with motor running: multimeter leads connect to above Y/G & R/G wires
5) second AC voltage test: Y/G & other R/G wires

The alternator stator wires do not connect to ground. For an AC voltage test for a disconnected alternator, the multimeter leads on ground and any of the alternator AC outputs (Y/G, R/G, R/G) will give not give a reading.

If the battery is flat or bad you won’t get very high voltage readings when checking for DC voltage with a running motor.
Make sure the battery is charged up before doing the DC voltage test.

[malky]

Cheers Jabcb the battery is still keeping fully charged and is currently on 12.7volts - I'll check the output from the alternator between the leads when I'm next down the garage I was earthing the black lead last time instead of plugging into both alternator leads at the same time