4agze Alternator Not Charging

[ryguy86]

Hello & HELP

I just finished an engine coversion on my 86 and put in a 4agze... the motor is running sweet, so no worries there.. but for some reason.. i cant get the alternator to charge the battery... as far as i am aware.. its wired up correctly.. but its not delivering 14.5 volts on run...


assuming that the alternator is actually working correctly... what could it be???


and other than strapping the alternator to the motor is there anyway to test an alternator to see if it works?



Cheers,

Ry

[feral4mr2]

did you use the external regualtor?

[4agte]

is agree with feral definatley sounds like the i/c regulator isnt connected or is faulty this is common with 4ag conversions

[BradW]

What voltage is it putting out when the engine is running?
The actual charging voltage wont always be 14.5v. It is dependant on the state of charge of the battery. The best way to check it is to check the voltage at the battery with everything (including engine) turned off. Then start the engine and battery voltage should increase ( you may need to give it a quick rev to get it to start charging ). Next, with the engine running, turn on all your electrical loads, bring the revs up above idle and check the battery voltage. It should still read higher than the first reading (without engine running).

If the voltage reading drops when all the loads are on (and revs increased) then there is a problem. Also compare the voltage reading at the alternator with the reading at the battery.

[ryguy86]

Re: Did i use the external regulator???


Well, i have been told that i dont need to use it.. the guy thats doing the wiring advised that the alternator i have is off a seca and has an internal reg...


but ill try it and see how we go.

[Grant]

That's correct, the alternator will have an internal reg. Usually the wiring colours are:

White: +12 volts from the battery,
Black/red: +12V ignition (may also be black/yellow)
Yellow: connects to the charge light.

If all that checks out then the reg may have failed.

[ryguy86]

does this mean that if the internal reg has failed...

i can use the external one instead?

[Grant]

No. You will need to replace the internal regulator. Most auto electrical trade places will sell them and they are quite easy to swap yourself.

[feral4mr2]

sorry you made no mention of useing a different alt in your opening post. the 4agze one uses a external regulator.

seeing the gze uses an external regulator you would think it would wire up slightly differnt to that of the one being used.?

[Grant]

What 4AGZE uses an external reg? Just about all Toyota engines from 1985 onwards used internal regulated alternators. My series II 4agze definitely used the internal type.

[Valkyrie]

Hi,
Ryuguy86 what model of 4AGZE do you own?

My MR2 4AGZE has an external regulator.

Cheers,
Justin

[feral4mr2]

indeed, the aw11 gze uses an external reg.
on the aw11 the idiot light to trigger the alt wires into the reg, not the alt. it's a yellow wire. the main charge wire (white) is tee'd from the alt to reg wire and has a fuseable link near the battery.
do you use a fusable link on the charge wire? have you checked continuity of the white charge wire ryguy86?

[30psi 4agte]

you need to check the charge being put out at the back of the ALT ( the stud with the nut on it) and see what it is !

If your battery is faulty or stuffed you may not see 14.5 volts at the battery even though your alt is sweet.

[ryguy86]

Hey People.

Thanks for all of your assistance...

After all of this.. the one wire i forgot to put on was the black and orange to the ignition.. so its charging now!

- what model engine do i have..

its a 4agze out of a AE92 Levin.. so its the last in the series.. has coild pacs- DLI.

and it goes HARD!