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alternator upgrade

Posted: Thu Oct 29, 2009 10:23 pm
by jbates58
hi all



i am looking to upgrade my current gq alternator, after dooing my head in for the past week trying to figure out why my alternator wont supply the power that its rated 2 on the sticker, im just going 2 upgrade it.



first off, i'll explain the charging prob, and then what i want to do.



so, i was out wheeling a couple of weeks ago, and i left my car idling for about 30m 2 direct some of the group i was with, in this time, using only idle revs, a/c and radio and uhf, my bat voltage read 8V on the dash gauge. and it didnt peak up above 14V and it still hasnt today, in the meantime, i have fully charged my main battery, and rewired my dual battery VSR's to a switch to disable them when i am using my ac charger. and i have also upgraded the alternators Charge wiring, woth wire capable of 150Amps, and the sense wire capable of 50Amps. so there is no trouble with that. i added my wiring in and also left the existing stuff there, so to prevent further porblems. and new wiring goes directly to the battery. now, when my engine is running, at 2000RPM, (and my maths kinda worhs with it aswell) with my HID spotties (7A) Rocklights (15A)[soon changing to led], Headlights and High Beams (??? im guna gues 10A per light so 20 total.) and radio and uhf, (guessing 5A tops.) and A/C (guessing aprox 15-20A) thats a total of 67A we'll rount it to 70A now, my maths tells me that there is 5 amps left that the alternator should be using to charge my aux battery, but it isnt putting out the power, its actualy not even coping with that load, and my battery is draining. but if i back off some accessories, like the rocklights, that gives me 50A, and i think that there should be sufficent power there for the alternator to charge the battery. but the power goes down to about 13.1V and my VSR's dont kick on until 13.7V. but, im my mind, and to my understanding, the alternator should be pushing out up to 75A at 14.1 - 14.4V and charge the batteries.



does anybody have any suggestions?



now, for what i want to do,



i want to upgrade it to 120A so i'll have plenty of juice for any ocassion. what are my options? as i need the vacume pump on the back, but i have read somewhere about vacume been taken from the engine, and not the alternator. what is the go with this, and can i do it? as i think that will leave me with a larger selection of alternators.



end of rant



Cheers



Jbates58

Posted: Thu Oct 29, 2009 10:40 pm
by big red
isn't the GQ alt only about 50 amps?

auto elec can upgrade to about 80.

GU has vac pump on different front cover of TD42 motor.

i fitted another alt below the power steering pump on my old GQ and had one alt running each battery which were joined with a solenoid in case i needed to dump the power from one to the other, had no hassles running everything connected up together and was the best dual battery system i ever tried :armsup:

Posted: Thu Oct 29, 2009 11:10 pm
by jbates58
hi all

unfortunantly i cant install a second alternator, as i have an endless air setup, and that is under my power steering pump

but good thought though

cheers

jbates58

Posted: Fri Oct 30, 2009 12:20 pm
by SLASH
My stock alt is a 70amp in a 98 GQ but i dont have the vacuum pump on the back. Theres been a few posts on this & im sure it can be done. From memeory AEA do one with the vacuum pump with very little mods to fit, check out there website. Or you can do away with the pump on the alt & then skys the limit with choice of alt's. That would probably work out dearer though. Cheers Loz.

Re: alternator upgrade

Posted: Fri Oct 30, 2009 12:46 pm
by bogged