Hi everyone, first off all sorry for the lack of punctuation i'm on my phone. Secondly my water tr wagon wont charge the battery. I've changed the alternator with two good ones to no avail. The fuse isn't blown either. What could it be?

assume you checked the obvious... you tried a different battery first right?
and checked the connections on the battery?

Check the cables to :) Might be a broken cable to the alternator :D

Yeah we did also checked the battery to alt wire and was fine but when i tested the regulator plug but got no voltage would a blown dash battery light be the cause?

I wouldnt think so. As indication lamp not a protection device.

would a blown dash battery light be the cause?

Yep!


I wouldnt think so. As indication lamp not a protection device.

IIRC from reading in years gone by, the small current in the instrument cluster ALT light circuit is what gets the alternator field coils magnetised (slightly) and initiates the whole electrical power production process.

Yep!



IIRC from reading in years gone by, the small current in the instrument cluster ALT light circuit is what gets the alternator field coils magnetised (slightly) and initiates the whole electrical power production process.

I think you're remembering back to Volkswagen days when the regulator was external. Workshop manual suggests that initial rotation of the fields initiates current flow and makes no mention of the warning light. But stranger things have been known to happen.

Careful when you check the cable from the battery to the alternator. Corrosion can be a killer in there. Experience tells me that

I think you're remembering back to Volkswagen days when the regulator was external. Workshop manual suggests that initial rotation of the fields initiates current flow and makes no mention of the warning light. But stranger things have been known to happen.

lulz VW had a generator, a totally different beastie. lol
You need some magnetism in the field coil to start the process. Field coils are stationary, by the way.


http://www.free-homemade-energy.com/wp-content/uploads/2009/07/alternator-diagram-300x242.gif

Not too helpful . . . .

If you look at a circuit diagram of an alternator, you will see the warning light is part of the circuit.

http://www.tb-training.co.uk/images/Image138.gif

No globe, no starting current through the sliprings, no rotating magnetic field, and no output. Simple!

Madmax is dead on, it was that light! Changed it and presto 14.4 volts. Also its supposed to say mates tr wagon not water haha.
Thanks to all that read/replied to this.

Well I learn something :) cheers madmax.

Well I learn something :) cheers madmax.

Did I just out-spark Sparky? lol
Challenge for you Sparky: predict what happens inside an alternator if the battery is connected in reverse. lol

I'm a sparky not an auto sparky :P There are something I don't know about :P

I look at the circuit diagram tomorrow :)

I'm a sparky not an auto sparky :P There are something I don't know about :P

I look at the circuit diagram tomorrow :)


OK then.
Do you do house calls? I've got some 240V wiring that needs checking and then hooked up. I live in Adelaide. lol (JK BTW)

Actually, I bought an interesting gadget on eBay. I plug it into a power point, and it shows me its wired up correctly. Also lets me test earth leakage circuit breaker trip current. All powerpoints check out, all circuit breakers trip at 15 mA. Useful gadget, but you probably know about them already. lol