R32 alternator issue...

[CerealKiller]

hey guys, I had my alternator replaced last year as the old one died. It's been working fine but I do have a few issues:

- when I start it in the morning the battery light on the dash NEVER comes on. When I crank it, it sits around 12.5V which is awfully low, it will go to the "normal" 13.5-14V once I've given it a bit of a rev. Surely I should have to do this?

- When I drive I notice that my voltage is about 0.5V less than when I started the trip, even less if I've been using my headlights.

- Recently when I've been braking my voltage drops to under 13V which I don't think is a good thing.

Any suggestions? I have a negative grounding kit on my battery and my battery is an Optima D34M (big deep cycle battery). I drive about an hour in the morning and night to work and about an hour after work...so my battery should be getting plenty of charge.

[Sumo]

Sounds like something is missing. I know with the bosch altenators if the light is not hooked up sometimes you could get the alt to start charging with lots of revs, but what a light does is help it pull in at idle revs. My R33 charges at 14.4 Volts at idle.

Did the alt you replaced with your old one have the same pin config? Sometimes they can be arse about face.

Cheers

Sumo

[Cubes]

When cold mine sits on around 14v. Once warm it sits around 13.2 to 13.8 but generally smack on 13.5 during the day.

13.5v is apparently the best voltage for charging the battery.

[CerealKiller]

hmm...thanks for your replies guys, I'll have a word to the mechanic that replaced the alternator.

[Sumo]

Cubes depends on the battery. The batteries with the yellow tops in a falcons have Calcium in them and need higher voltages.

I wouldn't say 13.5V is the optimum voltage for a charging system.