I HAVE A 1995 OLDS MINIVAN THAT IS CHARGING AT A HIGHER VOLTAGE. THE VOLTMETER (ON THE DASH) JUMPS FROM 15 VOLTS TO 18 AND HIGHER. I REPLACED THE ALTERNATOR AND THAT DIDN'T HELP SO I RE-INSTALLED THE OLD ONE, THEN I REPLACED THE BATTERY AND THAT STILL DIDN'T HELP. CAN SOMEONE TELL ME IF THERE MIGHT BE A VOLTAGE REGULATOR OUTSIDE OF THE ALTERNATOR? WHAT ELSE WOULD CAUSE THIS, MAYBE A LOOSE OR CORRODED GROUND ? ANY HELP WOULD BE GREATLY APPRECIATED. THANK YOU

 

Kill the caps.

What brand of alternator did you use? If it's not a Delco rebuilt, it could be as bad as your original.

What are you using to check voltage output? If it's the dash gauge, we've got problems, Houston. The dash gauge is not accurate. You need to use a digital meter to check output