A/T Oil Temp, Brake, ABS Lights ON. Battery 18v!

[rgk]

Hi all,

No fault codes stored or pending, but the above lights are on.

After 6+ years, my battery finally bit the dust. When I jumped it, the A/T Oil Temp, Brake, and ABS lights were off and the alternator was charging the battery just fine, 14v.

I trickle charged the battery, but it wouldn't charge over 3v, so I replaced it with a new one.

I put the new battery in, and the lights are back. I just checked the voltage and it read 18v while the car was running!

Is this a bad voltage regulator, and should I replace the alternator, or should I be looking at something else?

Thanks!

[VStar650CL]

There's no external regulation on an '02, the alternator's regulation is internal. So 18V can only come from a bad alternator. Don't run it for long that way, stuff on the CANbus will definitely start blowing up.

[rgk]

Great, I'll get an alt ordered ASAP.

I have not run it long like that. It definitely doesn't sound right.

Thanks.

[Mike W.]

Just to make sure, check your voltmeter. I've seen some digitals that would read high when their battery was bad, 16 or so, engine off, so a reading of 18 is believable when running. Just a quick check of another vehicle, you don't need instrument grade precision.

[VStar650CL]

Just to make sure, check your voltmeter. I've seen some digitals that would read high when their battery was bad, 16 or so, engine off, so a reading of 18 is believable when running. Just a quick check of another vehicle, you don't need instrument grade precision.

+1, good thinking.

[rgk]

Multimeter is good, regulator is bad. Thanks guys.

[04pathse]

Multimeter is good, regulator is bad. Thanks guys.

do you mean the alternator is bad?

[VStar650CL]

Multimeter is good, regulator is bad. Thanks guys.

do you mean the alternator is bad?

Same thing, they're unitized. Yes, the regulator inside his alternator is bad.