TB016 not charging

[Johnfused]

Hello,

My machine is not showing increased voltage when the engine is running. The tension on the belt seems ok but to change it, it seems you have to lift off the canopy and remove half the machine to get access so I'm thinking of cutting out the side with ventilation slots (and later fitting hinges). Here is a video of a guy who has undertaken the mammoth and ridiculous task of dismantling half the machine just to change the radiator, which it seems would be necessary to change the fan belt.

Red lines in my photo show proposed cuts. Not sure if they've loaded. Just made a screenshot of one of the photos and it has loaded; presumably the photo itself was too big.

Can someone please enlighten my darkness?

Infinite thanks.

 

[007]

A loose fan belt will only reduce the full output of your alternator, it will still excite and charge a little so even if your belt is in poor condition and firm in tightness the problem is not your fan belt.
Assuming your alternator is the same as the dude in the video.
Some of the most common issues with that type are.
Worn out brushes or brushes getting gummed up and not coming down on the slip rings.
Alternator warning light globe faulty which is used to excite the alternator.
Voltage regulator fail which can be internal to the alternator or external in the machine.
Fuseable link blown in the loom between the alternator and battery.
Check all of your fuses.
You need to do more electrical testing.
Cheers

 

[Johnfused]

Thanks you,!! Am posting without photos, it's just not working though I've spent ages annotating, resizing, but failed to load.

So you've eliminated the fan belt.

Alternator looks the same to me, like a car one, not a slim one like I've seen.

The brushes, etc., sounds like alternator talk. Have felt down underneath it and can feel the bolt (presumably that it swings on). The alternator warning light you speak of I don't see on the control panel if that's what it's called.


Voltage regulator must be inside alternator: in another thread as bout the same subject the guy finds the regulator underneath; I've taken a photo of the same place he's found his.


Fusible link looks fine and shows continuity.


There are 8 fuses, nothing to do with alternator so I didn't bother looking at them.


So will remove alternator after trying to test in situ, and see if I can test regulator.


Yanmar engine 3TNV70 STB
Takeuchi TB016, Year 2008, 1,544 hrs

 

[007]

Might save your self some work by testing it in the machine.
If you can take a picture of the back of the alternator i can talk you through it.
See if you can get close up to the one or two little wires which plug into the back.
See if you can catch the detail on the aluminum around the plug which some times tells what the wires are.

 

[Johnfused]

Wow, brilliant, thank you. Actually hit Reply to the email I received of your message fully expecting it would bounce back at me cos I should reply here but that was half an hour ago and still no failed message. Anyhoo, instead of rewriting wot I wrote I'll paste here.

Well pic seems to have attached. You can see the 'B' to indicate heavy cable from battery but I will look later during the day.

 

[007]

Your alternator looks like it is corroded and the battery terminal looks like it needs cleaning.
If you don't have a wiring diagram you have to work with what you do have.
By just searching (ND alternator) you get hundreds of pictures and diagrams you just have to match up one with same terminal block.

Alternator Parts Fit Toyota Landcruisr Prado 90 Series VZJ95 3.4L Petrol • $99.00

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picclick.com.au

has the internals of what you have i think shown in Pick1 and shows a internal regulator which is under all those straight fins.

Jatam Bila: Nd Alternator Wiring Diagram

xxxxx

jatambila.blogspot.com

Nd Alternator Wiring Alternator Denso Lucas Relay Nippon 6ra

Alternator gm chevy denso powermaster charging alluring marine backup fine diagrams s1900 2020cadillac gmc 1420 battery harness generator rewire aro Alternator wiring diagram: a complete tut

schematicrazmigamb6t.z21.web.core.windows.net

despite the different models most of them have (ignition, sense and lamp) being the three wires in that plug.
See if you can use your multi meter and identify each wire.
The ignition should be easy by just turning the key on and off.
Some times you have to use very small needles to puncture through the wires but just to identify them just press that button down at the top of the plug and pull it out and put your meter on the pins.

 

[Johnfused]

Hello, v. hard to reply with photos and text in order. Sent email to admin but has not appeared here. Also, can't put photos in correct order. Hope you can make sense.
Btw you mentioned that B post to battery needs cleaning but I don't see rust., etc.



Wire 1: WHITE + green stripe: 5.48 v
Wire 2: GREEN: 12.06v (battery is 12.32, low was 12.6 so probably battery drain.)
Wire 3: YELLOW + blue: stripe crazy all over the place

White stuff in plug. Dielectric grease? Discussion on Quota here:

https://www.reddit.com/r/mechanic/comments/x975y1

Well I had cleaned it from the plug before I had read this.
1st pic: removing plug
2nd pic: white stuff -- dielectric grease?
3rd pic: numbers to wires
4th pic: white stuff cleaned out, sprayed with contact cleaner
5th pic: one of multiple readings at wire 3 This will only accept 4 pics. It shows one of various extremely fluctuating voltage readings.

Now searching for what those wires connect to -- no luck so far.
Then maybe remove alternator (accessing lower nut will be working blind, fingers only), and see if I can get out the ... regulator(?).

 

[Johnfused]

Pic that was one too many for this post. Actually this was a strolling screenshot made earlier trying to get txt and pics together. You can ignore the txt where the ordering of the txt n pics had to be jumbled. ..Getting the hang of editing replies so put in the pic proper. This editing function is only available for some minutes.

 

[Johnfused]

Time limit 60mins expired to add to previous.
Here should be a short video showing light up panel.

New video · Thursday, Sep 4, 2025

Tap to view!

photos.app.goo.gl

 

[007]

I have no idea what each wire is as i do not have a a schematic of your machine.
I told you to find the wire which goes on and off with the key. (IGN)
That only leaves one with battery on it and one down steam of the warning light which when grounded brings the light on when the key is on.
I have cut down a internet picture below to remove the clutter and make it easier to follow.
If you do not have those conditions at your alternator you will have to back trace in the wiring to find the fault.
You said earlier in the post (There are 8 fuses, nothing to do with alternator so I didn't bother looking at them.) I would suggest at least one of the fuses will have one these signals coming through a fuse.