3b bj73 not charging (2 Viewers)

[MAAZcruiser]

Had my alternator rebuilt as the brushes were basically nonexistent but still not charging. Exciter wire is getting voltage. Also replaced voltage regulator after opening mine up and seeing corrosion on some contacts. 24v truck

Not sure where to go from here. Any help is appreciated.

 

[MAAZcruiser]

My manual has a internal regulator on the alt so it’s a little tough to follow. But was doing a few tests.

new regulator has ~24v with the ignition on at green stripe, red stripe and solid white.

alt has ~22ohms between E and F(green wire?) and about 20 ohms directly between the slip rings

the green wire is the exciter wire correct? Should have voltage going to the alt?

this all seems fine. Any other test I can try?

Also what is this thing? Assume it should be grounded but wasn’t when I pulled off old regulator.

 

[lacalvette]

Green/white is the exiter (field).
If you have voltage on field that's mean IG (white/red) receive 24v from switch.
Sometime fuse box is corroded.

Can you check that you have a good ground on VR (white/black) Earth (resistance between white/black (truck side) to body.

Should have 24v on (white) B

How much voltage do you get from B+ on the alt when 1000rpm?

There is good thread here from Rudi about alt and voltage regulator.

I think that extra thing is a capacitor to reduce noise for am radio

Do you min if I ask where you did source this nice voltage regulator?

Edit : should have write test resistance between engine to frame , body and batteries too

 

[MAAZcruiser]

Green/white is the exiter (field).
If you have voltage on field that's mean IG (white/red) receive 24v from switch.
Sometime fuse box is corroded.

Can you check that you have a good ground on VR (white/black) Earth (resistance between white/black (truck side) to body.

Should have 24v on (white) B

How much voltage do you get from B+ on the alt when 1000rpm?

There is good thread here from Rudi about alt and voltage regulator.

I think that extra thing is a capacitor to reduce noise for am radio

Do you min if I ask where you did source this nice voltage regulator?

Edit : should have write test resistance between engine to frame , body and batteries too

Only getting a little less than 24v at the alternator. Same as the batteries are charged to.
If I’m getting 24v to the alt field wire at the alt and only getting 24v out of it at b+ the problem must be with the alternator?

got the regulator from a Toyota dealership close by.

27700-57080 - Regulator Assembly Gene - Boch Toyota South

Regulator Assembly Gene - 2770057080. Genuine Toyota® Parts & Accessories. Manufacturer Warranty. From the Dealership to your Door. Experts standing by.

toyotaparts.bochtoyotasouth.com

 

[lacalvette]

Thanks,

Was going to say that would be a good idea to remove the reg lid and observe in which position the reg relay is but since you have 24V at the field, that's mean VR is in full charge...
You could disconnect the B+ at alt so you will be sure you actually measure the output, might just be the battery voltage ...Maybe there is nothing from alt?
Did the shop tested the alt and called it good?

 

[MAAZcruiser]

Thanks,

Was going to say that would be a good idea to remove the reg lid and observe in which position the reg relay is but since you have 24V at the field, that's mean VR is in full charge...
You could disconnect the B+ at alt so you will be sure you actually measure the output, might just be the battery voltage ...Maybe there is nothing from alt?
Did the shop tested the alt and called it good?

Turns out I am getting about 28v from the alt but only if I disconnect the wire from the b+ terminal.
Tried running jumpers from battery - to frame and alt housing but no change.

 

[lacalvette]

Alt seem to work fine with no load.
When engine rev below 1000 rpm it does not really charge, did you try running engine around 2000 rpm?
Not sure if a new VR need to be adjusted ( I would be a bit surprise).
Fusible link are good? Nothing wrong in the harness? (No modification, no work done recently)
Why did you rebuild alt, I mean is it still the same trouble...
Just trying to help...

Édit, can you re-install the old VR since it should be adjusted for your truck.
Edit: realise that it's in full charge...no ajustement needed.

 

[MAAZcruiser]

Alt seem to work fine with no load.
When engine rev below 1000 rpm it does not really charge, did you try running engine around 2000 rpm?
Not sure if a new VR need to be adjusted ( I would be a bit surprise).
Fusible link are good? Nothing wrong in the harness? (No modification, no work done recently)
Why did you rebuild alt, I mean is it still the same trouble...
Just trying to help...

Édit, can you re-install the old VR since it should be adjusted for your truck.
Edit: realise that it's in full charge...no ajustement needed.

Figured it out! Guess the guy that rebuilt the alt had the stack on the B+ post wrong.
Thanks for your help. Glad it didn’t fry anything

 

[fenwaykid]

Figured it out! Guess the guy that rebuilt the alt had the stack on the B+ post wrong.
Thanks for your help. Glad it didn’t fry anything

Education opportunity for me:

What do you mean by "had the stack on B+ post wrong"?

 

[MAAZcruiser]

Education opportunity for me:

What do you mean by "had the stack on B+ post wrong"?

The b+ terminal has a stack of insulating washers that were in the wrong order so one of the wires wasn’t making contact. Should have taken pictures but it’s all back together now.