Shindengen FH012AA Regulator / Rectifier Install

Note: This post was originally posted at
Note: The FH012AA regulator that I installed back in 2011 and referenced below has been superceded by the FH020AA which is the correct part to purchase now


After discovering how hot the stock regulator/rectifier runs, it's lack of reliability and possibility of battery fire upon failure I bought a Shindengen Mosfet FH020AA regulator/ rectifier kit. They are easy to find on Ebay, I bought mine from this guy: (if for some reason the link is broke, try this link for his whole MOTO-ELECTRIX ebay store

Search his store for FH020AA. I bought the universal kit which came with the gray and black Furukawa connectors, but if you end up getting an r/r by itself, just goto this website and get a connector kit:

        R/R Connectors  or EasternBeaver main webpage

The Mosfet design is superior to the stock SCR shunt design and more reliable since it runs cooler. Plus the Furukawa connectors are less prone to corrosion problems. It's also smaller and lighter, but the weight is offset by the adapter plate I used to mount it.

For further education on this subject here's a good thread to look at

Comparing the parts:


I started started by disconnecting the battery..VERY IMPORTANT!!

Next I made an adapter plate out of 1/4 aluminum with 9mm M6.0x1 Timesert thread inserts. Since the r/r isn't coming on/off the bike very much you could probably just tap the aluminum M6.0x1 but be careful not to over-torque.

Adapter Plate Plans - PDF Version Click here:
If you want to print and trace it be sure turn off page scaling when printing. The hole pattern is what is important, the outer shape of the plate isn't.

I kept mine solid aluminum to act as a heat sink, but then realized there's not a lot of surface contact on the back side of the unit.

 It looks like there would be good heat transfer, but then there's a .017" airgap between the cover plate and the mounting bosses.

So I drew up a version that could be made in carbon fiber, with holes for added airflow to the back of the unit. You could also cut an aluminum one to look pretty like this too. Someday I may make mine pretty, but probably not.

Since the thread inserts extend beyond the adapter plate, I had to very slightly enlarge the holes in the subframe as well as the holes in the FH012AA, using an "F" drill, but a round file would work just fine too.

Once I got it mounted I cut off the stock alternator connector.

I then used 14GA wire to extend the three yellow alternator leads, crimped & soldered the leads and inserted them into the connector.  I doubled up two layers of heat-shrink tubing to insulate and protect each solder joint. I don't want these wires getting exposed and arc-welding to the frame! I couldn't find yellow wire so I wrapped each wire with yellow tape - just for identification.

The kit includes wire and leads to run the DC output straight to the battery, but I elected to solder them directly to the existing wire harness for a cleaner install. The stock R/R output connector has two positive power leads (red wires) and two ground leads (green wires) plus a control wire (black/white wire) which is not used anymore with this modification. The two wires of each color are joined together elsewhere in the harness and I assume are double wires from the R/R only to increase amperage capability.

I cut the stock charging connector. CAUTION: You WILL get sparks if you do this while the battery is still connected - the red wires are HOT to the battery at all times regardless of key position.

I soldered together each of the red wires with the red 10 gauge wire from the FH012AA's connector, then also did the same thing for the bikes green wires to the FH012AA's black wire.