Classic battery no need purchase fail

ben · Post by **ben** » Mon Apr 11, 2011 6:49 pm

TXD sounded a bit slower than normal to start this morning, and on the way to work the windscreen wash wiper mode seemed quite slow ,so i measured the battery voltage at lunchtime and got 12.3 ,slightly less when the car was running.
So i bought a new battery down the road ,and fitted it tonight ,only to find 12.7 off the car,12.5 with it running . I did fit one of those cheap pos.terminals with the screws during the early part of last winter when my original burnt out a bit during jump starting another car , other than that i can't see any other cause for concern, the alternator (valeo) belt looks and feels fine and the car is regularly used on a 25 mile round trip every day.
So, alternator? If so how do i measure its output?

Post by **Defender110** » Mon Apr 11, 2011 7:22 pm

Yep alternator, should be getting 14.5v when running with the alternator charging.

Kitch · Post by **Kitch** » Tue Apr 12, 2011 12:12 pm

Just put a multimeter across the terminals when it's running. That'll tell you how much the alternator is dishing out.

ben · Post by **ben** » Tue Apr 12, 2011 2:05 pm

Cheers yes did that and get 0.2 less than when it isn't running. Was just wondering if there was a way of testing the alternator itself on the car to bypass any dodgy earths etc. Wiggled and poked about and even hit it, still the same so have bought another one off epay.
Keeping my now spare battery in the boot until it arrives