I washed my SG Saturday morning and polished the chrome for a ride down to a beach party at Surfside. I pulled in for a gas fill up and water break about 20 miles away from my destination and when I got ready to go, my ride would not crank with every indication of a weak battery. I had been on the road at freeway speeds for over an hour and had no indications of any charging issues. I was thinking that the battery may have been hot so I sat around for a while letting things cool down but there was just not enough juice to crank and fire. I pulled the seat and battery cover and checked all the connections and everything looked good. I got a jump from a Good Samaritan and it fired right up but I did not have any indications of a charging failure.

I rode a few miles over to Goe Harley Davidson in Angelton, Texas, and they immediately got on it to see if I needed a new battery. They checked it out and the charging system and reported that there was no problems, the battery was good and strong and the charging system was working correctly. I did not have any other issues after that...

They said that the hot engine and hot day may have combined to create the situation and once I got it running, things were back to normal. I have been working with electrical and electronic systems for most of my life and I have never heard this...I know air cooled engines are cantankerous on hot days and it is easy to drain a battery trying to crank them up but the engine never did crank fast enough to fire up so I am pretty sure the battery was not delivering full cold cranking amps and the voltage dropped to low to fire the firing system.

The HD battery was newly installed by the dealer when I bought the bike in December 2012 and the stator failed the following month giving me the check engine light in the speedometer and a dead battery surprise one morning. The stator and voltage regulator were replaced under the extended warranty. I also forgot to turn the key switch off one afternoon this spring and had to charge the battery before it would crank but I have not had any problems since.

Has anyone else had any problems with a hot bike not cranking on a hot day? I rode all last summer on super hot days without any issues.

I would be interested in all suggestions and will be checking everything out this week.

 

I'm having issues too Turn signals work no running lights brake light works no tail light and no head light again no blown bulbs or fuses

 

I've got a small LED voltmeter from Kuryakyn. It's has an adhesive back on it so I stock it on the front brake reservoir. and wired it into the tail light wire, that light is on when the key is on. It registers voltage only not amps, which is required to charge the battery. But at least I know what my voltage situation is. One of my pre-ride season inspections is checking connections on the battery and the connection from stator to rectifier/regulator. Also check the connections in the electrical panel for the wires from the R/R.

 

It was Murphy...

I checked the charging and electrical system from one end to the other and could not find any problems...until I turned on my fog lamps...they didn't work.

I had taken off my engine guard when I put on the oil cooler and I had to modify the right side lower mount of the engine guard to reinstall it. I did a quick modification on the guard and had put it back on the night before I rode it and did not notice that the bottom cover on one of the lights was loose. I checked that the lights were working and turned off the main switch without flipping the fog lamp switch off so the lights were energized during my Saturday ride. Sometime during the ride, one of the loose screws took a hike and the bottom cover on the left light got loose enough to start shorting out against the light socket terminals. This was enough to muck up the electrical system just enough to cause the battery to not charge before the fog light 15 amp inline fuse blew. Once the fuse finally blew, there was no more problem

Anyway, I took off the engine guard yesterday to make my lower mount modification look and fit better and that is when I noticed the bottom cover on the fog light loose...put it all back together with new stainless screws and blue Locktite and it is all good.

Murphy just had to remind me that he is still in charge...

 

Thanks for the detailed report. It reminds us to be attentive when we undertake modifications or other repairs/upgrades. Thanks again, it will help me to be more aware.

 

I love when dealers say, "oh that's normal, all Harleys do that"...

 

Yeah, I took what they said with a grain of salt...but I was impressed that they jumped right on it and would not let me pay anything for their time and trouble.

Piston airplane engines are serious high compression engines and can be cantankerous as hell on a hot day when they are hot...I have run a few batteries down trying to crank those things mid-summer. I ran my ride all last summer with out any cranking or running issues and I have never heard this about Harleys before...

I also know that a hot battery may not deliver full cranking amps...

I am surprised that the check engine light didn't come on letting me know that there was a charging problem...