Fixing the 'Splice' for Improved Charging

by Jerry Ferguson <>

Tools needed:

One of the very first things all Vmax owners should do is correct a factory wiring harness issue which impedes the Vmaxes charging system from doing it's job.  The issue is a crimped splice in the red power wire between the regulator/rectifier and the main fuse block which can cause resistance and a resulting voltage drop (Figure 1 below). It is located in the wiring harness directly behind the battery (under the front seat section) in a taped-up section of the harness. Many owners report a full one volt increase at battery during charging (when bike is running) by just soldering this connection.  Older bikes seem to benefit more from this modification.  All Vmax owners should perform this fix.

Figure 1 - diagram showing electrical location of 'crimp'


Perform following steps to correct 'splice' issue:

1) Remove front seat section from motorcycle

2) OPTIONAL - Start the motorcycle and measure the voltage across the battery while bike is running. This is the charging voltage.

3) Remove 2 10mm bolts holding rear coil assy (Figure 2 below). You will need to unplug some of the various electrical connectors which limit the rear coil assy from moving so you can get underneath to the taped area of the harness

Figure 2 - Picture of area under the front seat section



4) Follow the 'culprit' wire into the wiring harness to locate area where electrical tape needs to be removed (Figure 3 below)

Figure 2 - Picture shows routing of 'culprit' wire into harness under

rear coil assy (rear coil assy is lifted up for this picture)


5) Remove electrical tape from the harness until the red 'culprit' wire and 'splice' area are visible (figure 4 below)

Figure 4 - The 'crimp' exposed


6) Solder the crimped connection making sure adequate solder flows into the 'crimp'

7) Re-tape the harness with good electrical tape

8) Plug in any electrical connectors that were previously unplugged, re-install the rear coil assy with 2 10mm bolts

9) OPTIONAL - Start motorcycle and measure the voltage across the battery. Note any difference from step 2 above (if performed)

10) Re-install front seat section and go for a long ride, stopping only to eat, fuel up, or, well, you know. Have fun!