Hi folks

I'm looking for some information on wiring an alternator up.


here is my thread at datsun1000.com
http://www.datsun1000.com/TopicView.asp?TopicID=1108

Asking over here to cast the net a little further to get information

Anyone got advice on the Mitsubishi alternator?
The mitsi unit is a 50 amp output so more than enough for this task.
The Prado unit is overkill and a waste, but if thats what i use then fine.
Also, the prado unit may need some fancy computers or something to work correctly.

Mitsubishi was a factory supplier for Datsun production. So there are mitsu alternators that bolt right up.

If you choose a 60A mitsu alternator with FN connector it will plug into the 1200 wiring harness.

Thanks DD for the always rapid and spot on info, however

I should have been a little clearer on the question.

I'm making a battery charger setup with the spares at home.

Well if you use an LS t-connector alternator, you only need three wires
* positive to A/BAT and S
* negative to E
* 12v light between A and L
Per Basic Alternator Wiring

Don't forget a Fusible Link for safety. Won't blow like a fuse, but help prevent fires.
You can use a generic $3 link.

But you also need a small charged battery (or other 12V DC source) to initialize the charging. If the batteries to be charged aren't too run down they will be enough.

Thanks DD for that.
Ive been trawling the internet all afternoon to find these answers, and you provide them in 5 minutes.

The fuse you mention, I spose that should be rated to about 10 amps above the alternator?
Since its a 50 amp alternator, something around the 55-60 amps should allow for spikes to 100% duty but not blow the fuse all the time.

As for the amp meter guage, would that sit between the chg lamp and the ignition switch (in the diagram above)?

Cheers
Ill post up some pics once its all going, hopefully next weekend ill get some more time.

Dont use a a fuse. Use a Fusible Link

Instead of a Ammeter, use a Voltmeter across the battery terminals. Ammeter is secondarily useful and would go between battery POS and A terminal.

volt/ammeter
Was thinking of using one of these volt/ammeters. Would be accurate enough and dirt cheap.

or one of these
volt meter

Looks good to me. Voltmeter will tell you how the charging system is working.

Ammeter will indicate when the battery is done taking a charge. Although after 15 minutes any battery should be done, with no danger of overcharging. The built-in regulator means a precision charge.

Should work much better than a typical 120V mains charger.

ok so some feedback on this

Got the alternator wired up as per the diagram (thanks DD) and after getting some volts into the target battery (via regular battery charger), it all work a treat!

Charge light comes on, when hooked to a battery, but not running. As soon as I start the motor, the charge light goes out and the alternator is charging away.

But... (there is always a but)

It seems that the alternators internal regulator is shot. Voltmeter shows 17-18 volts going into the battery. Bugger. So Im looking for another internal reg alternator for this setup. About 35-50 amps is what I want.

And, it seems that 1/4hp electric motor isnt enough. After running the setup for about 15 mins, the old motor (that i fished out of an old spares bin) got far too hot and started to struggle. So i also need a more powerful electric motor. Bugger.

So, all in all, the concept works as designed, and for zero cost. So I think I have achieved my goal here. its justa pity that I need to find another internal reg alternator and a bigger electric motor. by the time I purchase those two items its getting to be an expensive project.

I've got a 120 amp Prado alternator sitting here in the shed (brand new!) that i could use,(but thats such a waste and overkill) but i still need a new motor.

Anyone in Perth want to donate to the cause?

A 120A is going to require 2.2x the horsepower to drive.

May I suggest a wrecking yard alternator of 35A. Here they came in /720. And in Japan came in Sunny Trucks til 1995. Perhaps in your country they came in small cars, Like 1986 Subaru Loyale.

Mistubisu
Hitachi
Terminals on back marked L and S are internally regulated