Voltage spike

[Rustyiron]

I had started the car monitoring the charging voltage and it was hovering around 13.8V and all of a sudden the dome light became really bright I looked at the voltmeter underneath the dash and noticed the needle at 16V for a few seconds then returned to normal. I am thinking the voltage regulator is acting up and needs to be replaced. It is a square back alt and two wire 70 style charging system.

 

[Paul_B]

Had a voltage regulator do something similar when it went bad. Also check your grounds to make sure you don’t have a bad connection.

 

[Rustyiron]

I had the alternator tested and just replaced the engine harness with a new M&H and verified all grounds so the only thing that has not been replaced is the VR so I suspect it is flakey.