Alternator Question on Vigo alternator

[janerasmus]

Hi all, I have question to ask,does the alternator of a D4D 3,0 fit on a D4D 2,5?

[Mars]

I am not 100% sure but it should as the 1KD FTV and 2KD FTV engines are almost identical mechanically. They take the same cambelt and tensioner and as far as I know also the same serpentine belt (if it has aircon as well).

[Mars]

Toyodiy lists the part numbers as follows:

3lt - 27060-0L020 (80Amps), 27060-0L050 (70 Amps)
2.5 - 27060-0L021 (80 Amps), 27060-0L60 (70 Amps)

I looked at images of both and there is no apparent difference.

[janerasmus]

Thanks, why I asking is that my 3,0lt give approx 14,2v at idle and the 2,5lt 13,8v, and if I want to use the 2,5 for towing, because it's n d/c 4X4 ,and make use of a duel batt system with a deep cycle battery ,the charging rate is to low?

[Mars]

The voltage that you measure on the alternator changes as the state of charge of the battery changes so it is a problem to try and compare the two engines as everything which has an influence on the voltage the alternator is delivering at that moment is not exactly the same. All that the voltages you are measuring tells you is that both alternators are charging. As a matter of interest, did you check which version is in which ie 70 or 80 amps? Not that the current output has anything to do with the voltage.

According to my understanding it is much better to use a DC to DC charger if you want to run a dual battery system as the alternator is not able to fully charge a deep cycle battery exactly because of the fact that the voltage is reduced as the battery reaches a state of full charge. Even the one in the 3lt will not be able to fully charge the deep cycle battery which over time ultimately damages the battery.

The other benefit of running a DC to DC is that you do not need to use the very thick cables to the second battery and if you choose the right one you can even add solar panels if you choose.

[Mars]

The guy to really ask is Chrisf but I am sure he will chime in here soon.

[ChrisF]

A standard high cycle battery in a vehicle will be "cooked" if the alternator delivers 14,5V.

Thus a standard alternator will either damage your primary battery, OR your deepcycle wont charge fully .... bit of a catch22 situation.