Battery Voltage Fluctuates

[Gunns VC]

Hi Guys,
My bro's battery voltage in his VK fluctuates alot, sometimes it goes up in sync when he revs the car or accelerates or if he's just cruising it will bounce from just over 12v to right off the guage above 16v. What could be causing this? A dodgy ulternator? bad battery connections? It looks like he is flashing his high beams at people at night but its just the battery.

Any help would be great.

Cheers

[sweefu]

Sounds like altenator mate, because the volts are going up when the car is reving..

[vkberlina]

if it wasnt going above 13.8 and doing it i would say a slipping belt, but with that much change I would say a faulty reg in the alternator or a faulty guage. check the voltage with a multimeter and if its doing the same buy a reg for the alternator

scott

[ari666]

or a dude guage... 16V is pretty high. didnt know these alternators were even capable of that much.

[immortality]

yeah, double check the actual voltage, if it is out then it is most likely the alternator regulator. also check the charge cable from the alternator to the battery.

[commodore nut!!]

my car did that too. i had to replace the alternator coz the regulator had gone kaput. sometimes also it could be the engine harness shorting. i have a power invenerter so i can have big powerful speakers in my car and the inverter used to go crazy when the damn voltage went up......good ol' commodores the endless money pit. but would never give mine up!!!!!

[Gunns VC]

Thanks for that guys. Ill go have a look at my connections and if that doesnt work ill replace the alternator.