3B 24v overcharging

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kzj70

kzj70

10 Year 15 Year
Joined
Nov 30, 2010
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13
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67
BJ42 EU spec 24V
Radio blew the fuse and then I realised the wipers were running too fast, put this together and suggested too much voltage. Then I realised the pos side battery was boiling.

I’ve fitted a new voltage regulator but it has made no difference. Now a bit puzzled!

Alternator putting out 33.4V
 
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Update:

Today I had some help from some clever friends.
This is what we’ve found but still not sure of a fix so if anyone else has had the issue please let me know.

The original regulator was ‘fried’ The new one is also fried. So it appears that something/somehow too much voltage or a spike has overheated one of the windings in the regulator and destroyed it. The new one apparently suffered the same fate instantly.

I have had the vehicle about 6 months and had no issues to this point.

The charge circuit wiring diagram is below. The section highlighted I do not have! I have no charge light (not even a blank or place it should be) and thus I don’t know if I have the circuit highlighted. This would look to be the/an issue but it hasn;t suddenly been deleted and the charge circuit has been fine.
IMG_8306.webp


We are happy that the alternator is working and we think correctly but would be happy to swap it for one with an internal regulator if this would solve the issue, Is there an option for this off, say, a BJ60 or 70? It has the vacuum pump on the rear.
 
Are you 100% confident that the alternator that is fitted is definitely an externally regulated alternator? If in doubt, post a few photos.
 
duncanrm said:
Are you 100% confident that the alternator that is fitted is definitely an externally regulated alternator? If in doubt, post a few photos.
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Not thought about that! This is the plate on the alternator
‘
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Looking at the parts catalogue it isn’t the listed alternator and that number doesn’t show up.

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Could you post a wider photo of the alternator and including plug?
 
Given its age and appearance.. I suspect it is in fact externally regulated.

The conversion to internally regulated is a fairly straight-forward wiring change. Its worth considering just buying a new internally regulated alternator and doing the small mod to rewire. 24V with the Vac Pump though - its often a little challlenging to find a suitable unit.
 
Thanks. Hence looking into if the above Dyna one fits . Though not sure if it is internal or external regulated.

My friend has been reverse engineering the blown reg and thinks he might have found out why, will know more in the morning
 
The label is complete and I don't see the 'IC' which denotes an internally regulated unit.

I would get the alternator tested. They are very hard to find new and should be repaired if possible, not replaced with inferior aftermarket units.
 
@duncanrm best I have:
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My friend’s theory of a faulty diode pushing voltage up to the reg at N ( from reverse engineering the blown regulators) proved to not be the case so no further forward.
 
Thanks for the additional photos, they confirm its an externally regulated alternator, although @Eurasiaoverland had already done that based on part numbers.
 
Thanks. I have the manual but the regulators are not the issue the tests carried out show correct ohms across each test except the last where we had open circuit on both from the coil being fried. Alternator is now in the shop for testing
 
The alternator has been tested and no fault found. Next to run through all the ground connections and then through the rest of the wiring,

It’s been suggested to swap to an alternator with internal regulator, anyone know one that fits?
 
kzj70 said:
The alternator has been tested and no fault found. Next to run through all the ground connections and then through the rest of the wiring,

It’s been suggested to swap to an alternator with internal regulator, anyone know one that fits?
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That's annoying, but seems you'll now be looking for a short in the wiring.

Given that you need a 24 V alterator with onboard vacuum pump, finding a quality used one with IC will be tough, and very hard to find a NOS Denso unit.
 
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ToyotaDyna said:
I have an aftermarket one of you are stuck, brand new in the box with the vacuum pump on it, it was never used.

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Looking for a left hand drive diesel Land Cruiser?

www.instagram.com/canarianlandcruiserexports
Facebook: Canarian Land Cruiser Exports
Click to expand...
Im interested in where this came from, what unit is it?
and do you have a real website instead of the social media crap, for your landcruiser inventory? Trying to have a look but S.Media can take a hike
 
ToyotaDyna said:
I have an aftermarket one of you are stuck, brand new in the box with the vacuum pump on it, it was never used.

---

Looking for a left hand drive diesel Land Cruiser?

www.instagram.com/canarianlandcruiserexports
Facebook: Canarian Land Cruiser Exports
Click to expand...
Interested. Brand? Price? But shipping to UK would be expensive. I can but aftermarket from Germany. Pics of the pump, some of the aftermarket ones readily available here are for 3B but pump config is different to mine
 
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