Hey Im new to this site and already have mechanical questions. I let my battery go dead due to cold weather when I was out of town and I got it to crank back up and now the tach doesn't work right and the motor will idle fine but won't rev up and the lights flicker when it idles I'm new to the motorcyle world but trying to learn. I appriciate any ideas or suggestions. A little about my bike its a 1990 Softail Heritage with High Comp pistons a bigger crank, a six speed tranny, and a Hypercharger.
confused
- Thread starter Beaux
- Start date
Recharge the battery fully before going any further as opposed to jumping the battery to start it. If that doesn't do it chances are the battery needs replacing, a load test will tell you this that can be done at most auto stores for free. Check for any blown accessory fuses.
You may consider the addition of a battery tender in the future.
You may consider the addition of a battery tender in the future.
Take a trip through the self help forums for a lot of info that may help you.
This is a battery tender.
Battery Tender For Storage - Harley Davidson Community
Beaux,
That is probably it. Find the battery and see if there is a small gauge wire attached to the battery terminals in addition to the large gauge positive and negative leads. Trace that small gauge wire to see if it ends in some sort of connector that the charger unit you found in the bag fits. If so, you found your tender. After you have FULLY charged the battery on a regular charger (or taken it to a car parts place to have them do it and load test the battery), then simply plug the tender in whenever you are leaving the bike (you can even do that every night if you ride daily).
TQ
Most modern ignition systems use an Electronic Control Module (ECM) having low voltage threshold that will not allow it to work below 9V or so, to protect processor or it's internals from damage...a good thing! :bigsmiley24:
The tach only draws milli-amps (1,000ths) , the ignition system draws 3-5amps of current, and your alternator is already taxed trying to charge internally shorted cells in the bad battery. You can try to calculate the number of dead cells using an accurate voltmeter and checking while running(each cell (6 of 'em) is about 2.2V each). The alternator should be putting out around 13.0-14.5V (engine running) maintaining float charge, if everything is in good shape. A fully charged good battery with mild load (like the 4.5-5.5A headlight only) should read 12.6VDC (engine not running).
A good "live" method of a CCA (Cold Cranking Amp) load test, is to see how bright your headlight is when you are starting the engine and see how much it dims. If it goes less than 1/2 brightness to completely out, your battery voltage reserve is probably close to that 9V low voltage threshold, and diagnostics to check the battery, connections and charging system are in order.
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Mattman4403
Junior Member
I will probably get corrected by the learned ones (you know who you are) but here goes.
A severly dischardge battery will steal so much power from an alternator that it will starve out other electrical components (the coil) causing just a myrid of problems.
A severly dischardge battery will steal so much power from an alternator that it will starve out other electrical components (the coil) causing just a myrid of problems.