My old alternator is not up to the job anymore and is running my battery down flat. It's only running at about 11 volts charge on the volt gauge.

I am wondering if there is an upgrade to another model alternator which is easy and inexpensive, with a greater capacity, or am I better of getting mine serviced, or maybe an exchange or new unit?

I run a Sigma one on mine... not sure of the exact details, but it's higher output than the 1200 one, and a bolt on fit.

I think i'm running a b11 sunny alternator currently. They're cheap and i think available up to 80 amp(?)

i was using a ca one for a while i just changed the pulley on it and it was fine

Sure, there are plenty of options, and plenty more powerful alternators. In the club wiki search for alternator.

But why do you need "more capacity"? I'm running the 35-year old 35-AMP alternator and it puts out plenty of power for a Datsun 1200.

have it checked might be just the regulator

a good thing to check is how much AC voltage you have at the battery, that will give info on what is going wrong... in bad cases you can see 15 volts of AC at the battery which would be an indication of diodes in the alternator being fried...

Well I have not had it profesionally Checked yet, but on my VOLT Gauge, it only reads about 11 - 11 1/2 volts, but the two times it has failed me was :
1) Driving at night with lights on. ( Quartz Halogen )
2) Hot day with electric fan on, there's no engine fan.
So I am assuming it is not charging enough voltage to run these electric items and the power is coming directly outr of the battery.

sometimes the piece of wire to the battery gets old and crappy and causes the battery to not charge too...


does the alternator light come on?

11 volts is too low. A properly working charging system must be 13.5 to 15 volts when engine is running above 1200 rpm or os.

Now the problem is usually one of two things:
* Alternator (less often)
* Regulator (more often)
Don't pay money for a new alternator when it is more often just the regulator.

Less like it could be bad wiring. Check the voltage at the alternator, not at the battery. If it is 14V there, but only 11V at the battery, you have bad wiring.