Battery Shmattery -- why won't my battery light go off?

[Michael]

First, I replaced the stock headilght bulb with a new fancy super power bulb.

The battery light came on.

Then, after realizing I really don't get any additional light anyway, I put the stock bulb back in.

The battery light was still on.

I purchased a new battery (I've been meaning to anyway).

The battery light is still on.

Now I'm not sure what to do.

[He Man]

isnt that suppose to be low voltage? resulting from bad charging fro mteh regulator? what bike do u have?

[64duc]

  Check voltage at the battery with the engine running at 3500 rpm. Anything below 14 volts indicates a charging problem.

[Howie]

The "battery" light indicates a charging system problem.  You could be under or not charging or the circuit in the regulator that turns of the light might not be functioning.  What year bike?

Also look here:
http://www.electrosport.com/technical-resources/library/diagnosis/fault-finding-guide.php

[Michael]

My bike is a 1996 m900.

Do I just hookup a voltmeter to the battery terminals to check the voltage? I guess I'll just rev it a bit high, I don't have a tachometer.

Also, someone recommended that I add an additional ground wire. Does anyone know how I might do that?

[64duc]

My bike is a 1996 m900.

Do I just hookup a voltmeter to the battery terminals to check the voltage? I guess I'll just rev it a bit high, I don't have a tachometer.

That's the way. it should read slightly over 15 volts. if the charging system is not working it will read 12 volts or less. Those older systems are known for weak regulators. You can unplug the alternator from the regulator and test for continuity from the wires to ground with the engine off, then with the engine running check for voltage between one wire and a ground.(the engine case will do)  if you get voltage there replace the regulator.  Assuming you have already tested all the fuses.

[Howie]

Make that 13.5 - 14.5 volts.  If you read less, area you want to check is where the yellow stator wires connect to the regulator.  That connector is prone to developing high resistance.  Also check the engine ground by the crankcase breather valve.  Adding an extra ground wire to the regulator should not be needed if the regulator mounting is clean and tight.  If output is normal, the circuit for the light is faulty, in which case I would pull the bulb and ignore it since later models don't have a light anyway. 

[scott_araujo]

Make that 13.5 - 14.5 volts.  If you read less, area you want to check is where the yellow stator wires connect to the regulator.  That connector is prone to developing high resistance.  Also check the engine ground by the crankcase breather valve.  Adding an extra ground wire to the regulator should not be needed if the regulator mounting is clean and tight.  If output is normal, the circuit for the light is faulty, in which case I would pull the bulb and ignore it since later models don't have a light anyway. 

You should probably open that connector, clean the contacts, and apply some dielectric grease regardless.

[Michael]

You should probably open that connector, clean the contacts, and apply some dielectric grease regardless.

That's a good idea.

I just picked up a multimeter from Harbor Freight (on sale for $2.99).

I'll let you guys know what I find out.

[printman]

I believe that the 96 has only two yellow wires coming from the stator (charging system) instead of three.  There should be close to 100 ohms of Resistance (Ohm setting)

When you disconnect the two wires to clean, set your meter to Ohm;s and touch red to one wire black to the other.

Since your already there, I mean. 

My regulator went out two days after buying mine (used) Electrosport was a great replacement and easy to install.

I have the LT Haynes on that model if you need some specs.

[Michael]

Thanks, everyone. 

My multimeter showed the battery was getting enough juice on high rev (about 14v).

I unplugged, cleaned, and dielectric greased all of the regulator's connections and I think that did it. The battery light went out on next start.

[scott_araujo]