DOC HARLEY: GROUNDS MATTER 

94 harley Davidson 1340 fxr good starter low output when trying to start maybe wiring grind

Thanks for sharing your success....Doc

Great info Doc! Cleaned mine on my 18 Roadglide Ulta today. With all the electronics, this is more import than ever. Used a dremel with a stainless brush head to reach in and GENTLY polish up the ground studs,.

Yes, we service any Harley-Davidson motorcycle that we have the tools and parts for (even Buells)

The starter motor of course is attached to motor, motor attached to frame, battery ground attached to frame. You CAN add a ground lead to one of the mounting bolts. Now the click click click….how old is your aftermarket battery? Have it tested. Sounds like your CCA are failing under pressure…..Doc

Good diagnosis 👍…..Doc

Mark nothing should go from negative to positive. If you are describing the battery tender connection, red terminal goes to the positive +, and the black terminal goes to the negative side of the battery. Thanks ~ Doc

My thoughts include what looks like security is really the BCM telling you a brake light is not functioning the way it should🤷‍♂️….Doc

@LowCountryHarleyDavidson All brake LED lights working. Flashers and blinkers. Yes it is BCM. I'm going to check secondary ground behind battery box on frame

Thank you…..Doc

connectors look a lot the same. check color wire going in and out. Sounds as if you have wires crossed...Doc

@@LowCountryHarleyDavidson only 2 out of the 4 plugs are the same and if i swap them i have nothing on controls so i know they are right the other 2 plugs are diff sizes im pretty sure the prob is not in the bars

Usually it has to do with the positive side. So dang hard to work with….Doc

@@LowCountryHarleyDavidson thanks. I already cleaned all of the positive cable contact points (battery and starter) and torqued everything back down, no change. It’s intermittent and not sure of the specific conditions to replicate it.

It is part of the BCM, Body Control Module

@@LowCountryHarleyDavidson ok , do you think it's a simple as a loose ground wire , or is that just something its saying because the BCM is faulty ? ......and THANK YOU !!

Battery too old . Regulator failure. Stator grounding. Connections loose. Thanks ~ Doc

Yes it is a reason…..Doc

In your manual, at the back in the Appendix, page B-20 Softtail Connector Locations......#31 under fuel tank.....Doc

It’s easy when you take the time to learn. Harley Davidson has a service manual just for electrical troubleshooting. It shows you the color of the wire. It’s place in a connector. Where and how the connector looks. How to assemble/disassemble it….if you can read and comprehend. It should be a walk in the park. It has wiring diagrams…. Don’t get me wrong. It can be intimidating but even a legend helps read their schematics. I say you pick up a book. Skim through it and you’ll be surprised how easy it is. I’m self taught. I’m always learning. But just today I learned how to read their schematics. It’s awesome! I can troubleshoot my bike w out having to take it to a shop. It might take me time. But that time will build experience. I don’t do it daily but sooner than later I’ll be more comfortable w it. There are still some things only the dealer can do. Like flash your radio to allow amplifiers to transmit sound to your speakers…. It’s proprietary software not for consumer use. But give it a shot. Search RU-vid for help. I’m here daily just for that. What he’s describing is clean ground and dirty ground. Clean ground is part of the cab bus system. Dirty ground is for your starter…. I just learned that today while going over the book Follow this guy. He’s good! ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-qdaOSiScEu8.html Otherwise. South Main Street auto repairs. He’s an automotive electrical genius!

Anthony not everyone is as advanced as you. Thankyou for sharing your vast knowledge….Doc