I need some help with a diagnosis for my 99 Road King. I was riding down the highway at 80 mph, turn on my fog lights and the engine all of a sudden went dead then a second later it comes back on with a forward lurch. This happen 2 more times and I got off the highway before it totally died. I checked the battery connections and they were tight but I went a ahead and took out the battery to check the other connections. I put the battery back in tighten everything up tried to start the engine but there was not enough voltage for the battery to start the bike back up. There was no power going to the lights or anything. I giggled the ignition switch and the lights came on very weak. The EFI light came on but when I tried to start it I just got the dreaded Click. I had the bike towed home. I did wash the bike that morning but had no problems driving my 30 miles to work in rush hour traffic. I haven't been able to check the battery voltage yet, but I am sure its dead. Has anyone else experienced this. I have worked on cars all my life and I would think that the alternator went out if this was a car. Any help would be appreciated. 99 RoadKing 88b EFI 63k miles no engine mods. The battery is 2 years old and I keep a battery tender on it.

 

Have the battery load tested first.
Check the ignition switch with a multimeter, I had one that went bad,
and my symptoms were about the same as yours.
I found out it was the switch by simple brute force. The bike had shut down
going 50, and I banged my first on the switch in desperation, then the bike came alive again!
Installed a new switch, all was good again.
Also make sure to check the ground cable on the battery at BOTH ends.
I had a sporty that the end of the ground cable was toast and caused
a similar condition.
Good luck

 

Welcome to the Forum.
Like Ragtop said, charge the battery and have it load tested. The next thing you should do is check the output of the Voltage regulator. Just hook a voltmeter to the battery terminals and run the bike at 2,000 rpm, the meter should read above 13 V and below 15 V. I have 3 bikes and checked them the other day and 2 ran about 14.3 V and the third 13.8 V.
If the VR voltage is less then 13V Check the Stator.

 

the Forums have a tech board.

in the electrical section is a sticky with full diagnostics-

https://www.hdforums.com/forum/elect...sting-1-a.html

be methodical. you WILL need a known good battery to get accurate test results

unlike most cars our stator and voltage regulator are separated.

we test for AC voltage at the stator and DC rectification at the voltage regulator.
but these need a good battery

and have a look at cables.

I have posted before a long story about a neighbor who spent $1300 at the dealer replacing parts.
10 minutes I found his battery cable was rotted internally

if is possible for a bad battery ( excess load) to take out a VR or stator...it;s possible for a bad VR to damage the battery, it is possible for a bad stator to d mage the battery if it discharges

welcome to the forums

mike

 

Check the 40 amp fuse that is located in front of the battery compartment. With age an extreme heat this fuse is easily trip. Went to the local auto parts and replace mine with a 50 amp fuse and have had no problem with tripping the fuse since replacing. That was 10 years ago. Good luck

 

he means circuit breaker I think for the 99.
not a bad thing to upgrade, circuit breakers get weak over time and may trip below rating- although that is a power on/ power off kinda thing. not weak lights


also the power to the lights etc runs through the ignition switch contacts- if extra high watt lighting is added up front, that can burn the switch contacts...try a wiggle test to see if better contact is made.
the ignition switch replacement can be a bother. if this is the problem you can get more life out of the switch by running all teh lighting off relays.

the 99 was also subject to a recall on the bracket for the tip-over sensor- this will kill the motor ( usually on a curve) but the lights etc will still work

mike

 

My Ultra did similar things. Battery was bad, chased other things first, ended up with a probable short in battery.