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Tech Article: Tyler Pennock's GEN1 Charging Fix
2001/8/20 12:00
From Mount Airy
Posts: 464
Level : 19; EXP : 95
HP : 0 / 473
MP : 154 / 27840

One sure fix for the charging problem on a VMax, (But also can be used on any bike using a 3 phase regulator), is that the OEM regulator is of a basic design, meaning it does not charge at idle, has no voltage control (just a fixed rate) and poor heat sinking.

OEM quick fixes are as follows;

1. Remove left rear foot peg bracket
2. Remove Regulator from bracket (the screws may be seized)
3. Sand the back of the regulator on a flat surface until flat and smooth Do the same to the mating surface of the foot peg bracket.
4. Make up a ground wire using 14 awg minimum wire long enough to go to either frame ground near battery and or the battery negative terminal.
5. Solder eyelets to both ends.
6. Get some thermal grease, and put a thin layer on back of regulator. Using new bolts, instead of screws,
7. Mount regulator back on the bracket Remember to put new ground wire under one bolt.
8. Re-install bracket regulator assembly.

OPTIONAL – you can solder the three WHITE wires Together. This is also a minor improvement, but I prefer to replace the connectors.

Start bike and see if the voltage, full output, is at 5000 rpm, But look for at least 13.4 at a bit lower rpm.

Venture Regulator upgrade;

First check for a mounting spot on the bike, recommended spot is the Left rear lower frame bar, you can fabricate up a couple of brackets to mount it. If you have a later model with a helmet lock, remove the lock and use it as one of the mounting points. Other than that it’s as much a bolt on, with a just a couple of wiring changes.
Locate a Venture Regulator, use any from 1983 to 1993, First thing you will notice it has more wires!! No problem There will be 2 Red, 2 Black, 3 white, one small brown.

Preparing the Venture regulator;

You will first have to remove the wires from the Venture connector as it does not match the Vmax connectors, you can re-use the one’s from the Vmax regulator;

1. Solder the 2 REDS together as close to the harness connector as you can get tape and/or heat shrink joint.
2. Do the same with the 2 Black wires. (another option listed below*)
3. Re-stall the 3 white wires into the VMax connector, making sure they line up with the 3 white wires in the VMax harness.
4. Install the RED wire into the VMax connector with the Heavy RED wire.
5. With an eyelet soldered to the black wire attach it to a good frame ground. *OPTION; If you chose you can also mount one to frame ground and the other Black wire direct to the battery negative terminal.
6. Now for the small Brown wire, if this wire is not connected properly the regulator will not function or not turn off. Next solder and tape or heat shrinks a length of wire to the BROWN wire (approximately 24” for trimming see the next step).
7. Locate a 12 volt SWITCHED power wire, at the fuse block, (the switched feed side) will have 4 RED wires, solder the new extended brown wire onto one of the RED wires after trimming the wire to the needed length. Tape connection.
8. Start Bike and do Voltage check , you should see 13+ volts at the Battery. If your only seeing 12.6-13 volts Regulator is still working properly, But you have Voltage drops in the main harness, This will be looked at next issue.

Lets say we’ve done all the above and it’s still not charging or charging is real low, around 11.8 to 12.2 volts. Suspect the Stator, the Vmax manual has a test for the regulator it’s confusing and a waste of time. If the OEM regulator goes south, only two things will happen;

1. No charge
2. Overcharging (15+ volts)

An open Stator will show low charging and a shorted stator can take out the voltage regulator over time.

Testing Stator;

There are only 3 things that can go wrong with a Stator anyone of them can cause charging system to fail. To test a stator correctly you need a GOOD Digital VOM (volt/ohm meter). There are many out there, look at spending at least $50.00 and up A couple of Companies to look at are B+K Precision or Fluke, These are higher end meters, But Excellent. When you go shopping for one the main thing your looking for is that it can measure Resistance (Ohms) of less than 1 ohm accurately. A good stator will measure between .22 and .35 ohms/per leg (White wire) and when measuring all three legs of the stator must read EXACTLY the same. A cheap meter will not read this. To test Stator it does not have to be removed, just unplug the 3 white wire connector from harness.

1. Select the lowest resistance (ohms) range on the meter, depending on the make and quality of the meter, it maybe 2 ohms or 1 ohm range;
2. Connect leads to the meter
3. Turn on the meter, touch the VOM’s leads together and note any reading, (this will be the resistance in the leads, if any, note the reading).
4. Connect the leads to any two of the white stator wires, note reading
5. Leaving one lead connected, move the other to the open lead, note reading
6. The lead you left connected, now move it to the open lead, note reading
7. If stator is good ALL will read Exactly the same, if one is lower or higher stator is bad and has to be replaced.
8. Last test, leave one lead connected (doesn’t matter which one) take the other and connect it to a good frame ground, if you get ANY reading the stator is shorted and has to be replaced.

This test should be done Before replacing the Voltage regulator.

For more information contact me at;


Posted on: 2013/11/5 13:43
Be safe out there and enjoy the ride....

Mike Moore
VMOA Webmaster

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