I have a 2001 Dyna FXDX. It was last running two mnoths ago -- no problems. It has been on a float charger since then.

When I tried to start it this AM, the electrical system turned on as expected and there was a momentary sense that the engine was turning over. Then a strange "clunk" and complete electrical shutdown. No current to starter, no lights, nothing electrical is working. I pulled the seat and checked the battery. It showed 12.5V and no indication that it wanted to be charged. There is a very faint smell like a blown capacitor. No obvious shorts, breaks or other indications of electrical failure. One very strange phenomena is that when the key is left on (either Acc or Run), the electrical system comes back on (lights, etc) for about 5 seconds once a minute or so.

Any help would be appreciated:

• where can I find an electrical schematic for this bike?
• any thoughts on what I should check first? I have ruled out a loose connection or similar by "wiggling" everything I can touch with the seat removed to see if something might trigger an electrical response. Nothing does

Thanks

 

https://www.hdforums.com/forum/dyna-...-part-1-a.html

Check the ground cable, it must be clean tight, just like the battery terminals.
Check all fuses, make sure they have continuity and clean tabs. Look at the relays, the tabs can get corroded.
Even if the battery shows 12.5 V sitting, it may not have enough cranking power to spin the starter. You can get the battery load tested for free at most auto supply stores.
You could have faulty/dirty ignition or starter switch.

 

Thanks for the reply. I have made some progress working my way through the starter system:

1. the system is now maintaining some electrical power once the key is turned to acc or run
2. I have checked every fuse and every connection in the starter circuit -- all look OK
3. main circuit breaker works
4. Ignition switch is OK
5. starter relay is working
6. + side of the circuit seems OK to the starter/solenoid
7. negative side cables and connections look good
8. solenoid seems to be receiving power and there is a distinct clunk when triggered
9. solenoid does not seem to be engaging and starter motor is clearly not turning
10. voltage across starter drops from 12.5V to approx 5V (some variation) when attempting to start bike

 

#10.

You always want to "load" test a battery.

If yours goes from 12.5V to 5V (when cranking), there's your problem!

It should drop to 11V or more. Over 12V is a healthy battery.

 

I have a 2000 FxDX, I had strange electrical problems that would randomly sit me on the side of the road. I replaced every dxmn thing, regulator , main fuse, relays, battery cables, etc. after having the battery load tested - twice. I learned a lot, the most important thing I learned was to replace the battery- first.

 

Thanks for the reply. The voltage drop test is an interesting test. I have read through several shop manuals on-line and a few isolated descriptions. All suggest that 2V is the critical "something" but some state a drop of 2V or more is bad and others a drop to 2V or less is good. The statements are inconsistent. The physics suggest that a drop from nominal of more than X indicates too much draw and a problem. So I interpret the drop test to mean that a drop of more than 2V from nominal indicates a problem. The drop test is a diagnostic that helps indicate a problem but is not a definitive test for what the problem actually is. The problem could be a bad battery or any number of bad intermediaries or a bad solenoid or starter. Since bypassing all the + intermediaries (switches and relays) has the same result, I am down to a bad battery or a bad solenoid/battery. So a new battery will be tried tomorrow.

Going directly to a new battery would have saved some time (if that IS the problem), but looking at everything has been valuable because it forced me to examine every fuse, every contact, every relay, etc., which was educational and is probably a good idea to do every now and then

 

Did ya try jumping it off a car battery (car NOT running)?

If it starts and runs, get a battery. If it don't, keep digging.