alternator upgrade

[grpa9x]

hi all,
I was thinking of putting an 80amp alternator in my gtv6, the car has standard electricals, will this cause any damage by just dropping it straight in.
thanks in advance.
michael

[Al Campbell]

Michael,

No it won't case any problems. The 80A just means what it is capable of delivering if required. The original wire from the alternator that goes to the terminal block on the bulkhead next to the brake booster is a bit thin, but you still wouldn't cook that anyway. The issue with the existing under-rated alternators is that when idling they don't produce much power and the voltage "droops". At moderate revs the old 55/65A alternator would be pumping enough power.

AL.

[MD]

In an absolute worst case scenario where you had everything running on your GTV6, the total current demand would be 85amps. This would come parly from your battery and your alternator at the same time.
An upgrade to a higher output alternator will usually help to lift B+ voltage around the entire car making things like indicators, wipers, headlights and the like work much better.

[Al Campbell]

Had a look back for past posts and a discussion it turned out I was having with MD about alternators and I measured a maximum drain with everything possible going of 59A.

[MD]

Hi Al,

Been having a serious think about this and then the answer hit me. You know the Queensland borders are bigger. Our coal piles are bigger. Our scores against the Blues are bigger (..er sometimes) so naturally the outcomes are bigger. So why should that suprise you ?? !!

Never lose that smile mate. 

[grpa9x]

thanks for your knowledge once again guys, i will fit it on the weekend.
regards michael

[grpa9x]

hi again,
well i fitted the upgraded alternator and now have a new problem, after about an hours driving the battery light began coming on whenever i slowed or stopped, once i got moving it would go out, this never once happened with the standard item. This new alternator was supposed to be refurbished . Any clues as to what the problem is, could the brushes be worn ??

[MD]

More than likely the charge light bulb is the wrong load to "excite" the alternator electically so it will charge. Talk to the people you got it form and find out what wattage bulb you should use for your charging indicator light. Don't sweat it...if it is a good alternator, all will be well.

[grpa9x]

hi MD,
thanks for your reply, i hope that is all the problem is.
cheers michael

[grpa9x]

More than likely the charge light bulb is the wrong load to "excite" the alternator electically so it will charge. Talk to the people you got it form and find out what wattage bulb you should use for your charging indicator light. Don't sweat it...if it is a good alternator, all will be well.

MD,
they say that as long as it is 12 volt the watts make no difference, they said to run a wire from the battery and touch the main wire at the back of the fusebox, if the dash light goes out i need to add this wire.Does this make any sense to you.
cheers michael

[MD]

as long as it is 12 volt the watts make no difference

Definitely don't agree with that. Try someone else for the same problem.
As for the wire to the back of the fuse box..er.. no idea and it sounds like the guy who gave you that advice has none either..

Do the basics first. Place a voltmeter across the battery terminals and see if the voltage drops at idle and rises with increased revs. If it does, it is charging and you should get between 13.8-14.2 volts. If you are not getting that at say over 1500 revs, there is either a problem with the alternator,or the load bulb (in the dash).

[grpa9x]

MD,
i decided to put the original one back in, the warning light has gone out so i will leave it in.
thanks again for your input.
cheers michael