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New alternater on the cards but....

Posted: 07 Jan 2011, 10:41
by Essex Nige
i've got an AAZ and the alternator puts out a lovely 14.3v without anything on an plumets to 12.3v once the lights and heater are in full swing so the alternator is knackered,

my question im running a syncro, with camping interior, maybe getting a winch etc, etc... is it worth uprating the alternator to a 90amp from a 75amp which it has now?

if so, what are the benifits as im a bit slow when it comes to AMPs and power usage and alike

Re: New alternater on the cards but....

Posted: 07 Jan 2011, 12:48
by kevtherev
You checked that at the battery ?
That 14v you tested says your battery and charge is in good nick.
So then you add few heavy loads onto the circuit and assume the worst.
Your Alternator is simply doing it's job, it providing the loads with the power they need.
The last thing that needs power is your battery. That did it's sole job of starting the engine long ago, and has recovered.

Personally I would fit the winch, use it and if it's wanting fit a different alternator, but my money's on it won't


Re: New alternater on the cards but....

Posted: 07 Jan 2011, 12:59
by Essex Nige
kevtherev wrote:You checked that at the battery ?
That 14v you tested says your battery and charge is in good nick.
So then you add few heavy loads onto the circuit and assume the worst.
Your Alternator is simply doing it's job, it providing the loads with the power they need.
The last thing that needs power is your battery. That did it's sole job of starting the engine long ago, and has recovered.

Personally I would fit the winch, use it and if it's wanting fit a different alternator, but my money's on it won't


Yep thats checked at the battery, i thought it had to maintain a current of between 13.5v - 14.3v under load or otherwise to top the battery up after cranking or am i talking complete toilet?

Re: New alternater on the cards but....

Posted: 07 Jan 2011, 14:20
by kevtherev
13.5v - 14.3v under load or otherwise to top the battery up after cranking
yes that's right.. for about half an hour. The rest of the time is trickle.
Power will always go to the drain.


How long will you be winching for... an hour ?

Re: New alternater on the cards but....

Posted: 07 Jan 2011, 14:33
by billy739
you did rev the engine for the test rather than idle?

poss the regulator , wiring , earth connections , battery ect

75 will be ok , but you need to consider the battery size and running time

even with a 90 amp alternator and a lorry battery(12v) short stop start journeys in the dark/rain will give you a flat battery