Battery drain test

[rado360]

1997 R1100RT---Checking a few things today and connecting a voltmeter to the negative post and to negative cable of my battery(with the cable disconnected from the battery) ,manual says voltmeter should read 0 volts,I'm getting 12.5 and when I turn the ignition on it jumps to 13 volts,voltage across the battery post is 13 volts.The Clymer manual says "check all componets of the charging system for bare wires which could cause the drain".

Why do you think the volt reading is changing from 12.5 to 13 volts when I turn the ignition switch to on and back to 12.5 at"R" position and back to 13 at "P" position?And couldn't the drain be someplace else than just the charging system?

Can anyone tell me where to find the plug for the ignition switch so I can disconnect it from the system,maybe that would tell me if it's the switch thats bad.


Thanks, Tim

[flash412]

You're supposed to be using your meter to measure AMPERES when you put it in series with the battery to measure leakage. Change the scale and read it again. Depending on your meter, you might need to change the hole into which one of the leads plugs in order to read current.

Oh... and if you turn the key on, you'll probably blow the fuse in the meter, if it has one. Or maybe burn it up.

[rado360]

Thanks for the reply, According to Clymer manual I'm supposed to connect meter bettween battery post and cable and be looking for 0 volts not amps?

Thanks, Tim

[bmwmick]

[QUOTE=Lowrider]Thanks for the reply, According to Clymer manual I'm supposed to connect meter bettween battery post and cable and be looking for 0 volts not amps?


Tim,
Set the meter to measure AMPs, not Volts. The plus lead of your meter should be on the Negative terminal of the battery and the minus lead should be on your disconnected ground cable. What you are measuring is the 'leakage' current of your electrical system. DO NOT turn the ignition switch on during this test unless you have an Ampmeter capable of measuring up to 10 AMPs of current.
Most systems should measure between 35-50 Milliamps with the ignition off.

HTH,

[rado360]

Thanks to flash412 and bmwmick I learned something about my electrical system.
Thanks guys