The brand-spanking new high CCA lithium battery started draining recently. It worked fine for a few months, the voltage drain is a recent phenomenon.

A board ninja suggested that the voltage regulator could be the cause, so I looked up the part number in the Harley parts manual: 74510-70A RECTIFIER AND REGULATOR ASSEMBLY -12 V. (chrome) .... .. ..70 to 75- FL, FLH, FX

Google took me to a pricey but supposedly high quality Accel unit.

When I started the swap, it became apparent that the Accel unit wasn't a direct swap for the existing one. They both have the 4-connector plug, but the long lead to the battery is different.

The Accel unit has only one black lead at the battery end.

The current unit has three leads coming from the end per the picture:








It also has an extra black lead about 10 or so inches down the sheath:








Here's what the current unit looks like:






Anyone know the part number for the current unit? When I search Google for the part number from the book, all the units appear to be one wire like the Accel unit.

 

Think you need to trace one of those black wires. Looking at the I only show 2 wires running off the OEM regulator (black and pink).

 

Looks like the old 4 pin Charging System to me!! Won't even maintain an AGM battery... [Mine wouldn't]
I would Update the whole mess [Rotor/Stator/Regulator] to CE or some other good quality 2-Wire [Not Accel] System

 

Thanks brothers.

How much a PITA is it to replace the entire system?

Major parts come apart or just a few hour job?

 

^ Complete primary removal is required, unless you find you can get the Rotor off with the Inner In Place... On my FXR you can!
4-speeds???? I cannot.
If you are still gonna use inexpensive Non AGM lead acid Battery, the system you have should be fine...
New ain't always "better" IMO
and it is Not an inexpensive Replacement to go to a System that will reliably maintain a Lithium Battery..
I still use AGM's... even if my system cannot maintain where it "should" be... they last about 3 Years... for $50.00?? I'm good with that!!!

 

What Racepres said...starter, primary chain, cluth hub, inner/outer primary. If you don't have a manual, get one. It's not difficult but is about a 3 hour job + plus you will need some specialty tools

You are not going to be able to get the stator off without removing the inner primary on your 75 FXE (owned one and upgraded electrical system and now have a 78 FXE).

Cycle Electric (American made) is the best on the market today. Accel is no longer made in the USA.

 

Spoke with Carl at Cycle Electric. He thinks the red wire drives the tach. My machine has an electric tach, so that makes sense.

Unfortunately he doesn't manufacture a replacement for my setup. I gather it's a bit crude in its operation, not really a voltage regulator.

I would consider converting to a CE setup, but don't want to lose the tach function.

Carl thinks my setup was produced from 70 - 74, so possibly my '75 was an early year model that was fitted with prior year electrics.

The headlamp is LED as is the tail/brake light, so only other current draw is the ignition.

The system seemed to keep the battery charged just fine until a few weeks ago, when it started losing enough juice overnight that the only noise was a clicking relay switch.

If I can find another regulator of the same design, that would be the easy way out. But I can't find anyone producing them.

 

Can you share a pic of the tach you are referring to and also a pic of the 3 wires where they run off your voltage regulator. Never seen what you are talking about.

This was my 75 FXE. Totally nuts and bolts stock sans the front brake master cylinder to caliper brake hose.

 

That's a great looking bike, Panz.

Pics of the wire are at the top of the thread. There is a red wire and a black wire exiting the sheath in the battery area. But there is also a black wire exiting the sheath about a foot down the wire near the rear exhaust as pictured above. At the regulator end, it feels like there are only two wires inside the sheath.

Here's the bottom of the tach

 

The Pink wire to the tach [on any Old Harley] is attached to the Ignition trigger side of the Coil... Only way a Tach can work is to count triggers..
You will Not loose the Tach by Updating that charging system..