Dead Sportster Battery

[glider.]

Service Bulletin TT322
July 26, 2007
2007 XL Models with Discharged Batteries or Very Low Voltage

Harley-Davidson has found some ’07 Sportsters where the batteries are going dead after a night of sitting. The root cause is water intrusion. Water can run down the harness, funnel into the fuse block area, and then bridge the system relay contacts. The system relay has constant power available on the 30 terminal.
When the system relay is activated, power goes to the ECM, and then the ECM sends power out to the IAC. The IAC will then run until the battery is fully discharged.
To prevent this issue, Electrical Contact Lubricant (p/n 99861-02) can be placed on the terminals and base of the system relay, and the receptacles at the fuse block. This will create a water barrier once the relay is installed into the fuse block.
Motorcycles exhibiting this condition could also have corrosion present, and if necessary, should have the relay terminals and receptacles cleaned with a wire brush or replaced.

 

[NEWHD74FAN]

Well, now we know the root cause. Most newer Sportsters have no cover to protect the fuse block from the elements. I was sure shocked when I had my first problem on my Sporty and traced it to a blown fuse (cut wire insulation in hand control ragged passthru hole of modified handle bar assy). Ended up replacing all of the 15A fuses (they were actually sun faded, all had evidence of corrosion)...cleaned contacts with BrakeKleen cleaner over rags, dry, coat w/dielectric grease and everythings fine and will stay that way.

Do this on all new Sportsters especially ones w/full side cover (older ones with separate battery and triangular "real" fuse block cover are probably better off, but you can do this maintenance tip for them as well.

 

[Libertycard]

I have been having a similar problem on my '07. It started after my third season of riding in the rain. Took 2 trips with dead battery to the dealer to get them to fix the corrosion prob on the fuse block. The Sporty runs ok now, and the battery stays charged.
But one day after the last rain, the speedo went dead again (second time this happened), and now only works after setting over night in the garage, but then goes dead after speed increases over 30 mph. It tries to run after starting up at stop lites, but dies right away.

I suspect water somewhere, probably still around the fuse block, but I don't know.

Is there a good waterproof fuse block to replace the exposed Harley block? Would upgrading the Speedo find/fix the problem?