shovelhead charging system

[Samueljaxon]

Hi all,
I have a question for anyone knowledgable on the the subject. I have a 1977 fxe that has never held a charge since i got it. Checked all loose and pinched wires for drains and moved to the charging system after testing is with a voltmeter. With a charged battery it will run pretty strong but put some stress on it ( a handful of miles or god forbid turning the headlight on) and it will eventually sputter out and be unable to start/run. It can't maintain 13 v in the battery when its running so my thought was to swap out the regulator after troubleshooting the stator as described in the clymer manual. Here is where my trouble confusion arises: I ordered one from jp cycle, it comes (as do all compatible regulators for 76-80 model on their site) with no prongs on the regulator side (female connection). The regulator i bought the bike with has male on the regulator and female on the stator/case side. So this one I bought seems like it wont be compatible. I tried slipping two appropriate length piece of 3/32 stainless welding filler rod to bridge the gap between the two females but still does not seem to be charging the battery- the connection with this seemed close but could have been not tight enough. (When mic'd the prongs read 11/100's of an inch when 3/32 is a bit short of 10/100.)

My question with this to anyone whos been around old harleys for years is was it at all common to swap out the entire charging system for those of later models when say the stator hit the bed? From what i can see the 1980+ models had prongs coming from the stator and female on the regulator side. Also what are the differences in these regulator besides this reversal of connections? Seems my next option is to buy one 1980+ with prongs but im wondering if anyone could enlighten me prior.

thanks, samuel

[JBinNC]

There have been a number of alternators from H-D since their introduction in 1970. At least four of those systems can be installed in shovelhead cases. Fortunately, each system has a unique stator/regulator plug, so a mismatch of the components is not possible. That is, unless you try to crutch the mismatch as you did. Each of these alternators has a different output amperage, so the components must match.

I think you have the '81 - '88, 22 amp stator in your motor, which is a good and common upgrade for the 18 amp system that your bike came with.

Your first order of business is to check out the stator for output and grounded or open windings.

Jim

[Samueljaxon]

I did check the stator for grounding and it wasn't but didn't have someone around to help me check is for output( manual recommends having a helper because excessive time running without connection to the regulator might damage components. I'll do this before moving forward though.

My thought was the same though that the system was entirely upgraded at some point. Do you know if this 22amp system could lead to any problems vs the ?amp that the 76-80 comes with. The bike is pretty much stock fyi.

thanks for your input, greatly appreciated

[JBinNC]

The 22 amp upgrade will not cause you any problems.

Jim

[TriNortchopz]

Look at stator options and plug styles here:

Stators

Cycle Electric Inc. stators

http://www.cycleelectricinc.com/

[JBinNC]

You can run the motor as long as you please with the regulator unplugged from the stator. That bit of advice from a manual is just BS.

Quick and dirty way to check the stator for output is to hook it up to a drop light (must be an incandescent bulb). The output of the stator is AC, on the order of 10V per 1000 rpm. If the stator is good, the drop light will glow and get brighter as the rpm increase.

Best way to check for grounds is with a test light. With the motor running, probe each terminal of the stator with the test light, with the lead grounded. If the test light glows, the stator is grounded.

Jim

[Samueljaxon]

Stator checks out, its got 15 volts at idle and more as I pull on the throttle and still no grounding. Looks like I'll get the proper 22 amp regulator next. Thanks for your help/ knowledge JIm.

[MIKESIERRA]

Stator checks out, its got 15 volts at idle and more as I pull on the throttle and still no grounding. Looks like I'll get the proper 22 amp regulator next. Thanks for your help/ knowledge JIm.

I kind of just went through a similar situation. I needed a new stator so I got a new cycle electric one. The plug was female and so was the regulator. I Jerry rigged it to keep me on the road til my new reggy came. That didn't last long as it burnt the connection between the stator and regulator leaving me to limping my bike back home.

Tl;dr Just buy new cycle electric regulator and stator and you'll never have to deal with these two for a long time.

[Samueljaxon]

Yes I ended up getting the 22 amp regulator and it’s running strong. Thanks to all who offered advice, much appreciated.