13bt alternator went south (1 Viewer)

[keving]

Hey. The alt quit charging on me the other day, well, got worse over the course of a week till the needle don't even register anymore, it moves a little once it warms up, but not charging.
its a 24v bj74. low mileage...I find it odd that the alternator is shot already. Any other things such as a voltage regulator I could check??

Thanks!

 

[simonliew]

Hi,
Usually the brushes are wornout,you can remove the brushes from the top of the alternator without removing the alternator,l don't remember but l think the minimun length is 12mm,you cam replace the brushes(two of them) with the holder or just buy the brushes and solder them on the holder.
l found both at local alternator rebuild shops.
Simon
Winnipeg

 

[keving]

Would you suggest replacing the brushes this way instead of taking the alternator out?

 

[prado t]

It could also be the voltage regulator, an alternator will give you signs of it going on the fritz, voltage regulators just go when they want to my 2 cents

 

[UpsideDown]

There are both IC and mechanical regulators found with 13BTs, I expect, as this is the case with other Cruisers.

Mechanical regulators are what I see most in BJ74s, and they don't tend to "just go" with no warning. Brushes are the most common cause of poor power output, and brush wear is related to engine hours and also somewhat to the amount of load placed on the alternator.

First thing I would check is the brushes and slip rings. Make sure the brushes are protruding beyond spec. Greasy or oily slip rings will make poor contact with the brushes and you will see low voltage output.

If the brushes look good (ie: they protrude about 10mm or more) then you should get a charging system test done at your local repair or auto electric shop.

~John

 

[UpsideDown]

Note that you should also check the fusible links and fuses (charge, alt, engine) to see if they are in good shape. You should also do a general check of the electrical connections at batteries, alternator etc.

A very common cause of a dead alternator is the old/dead/poor quality Japanese batteries that arrive in all the JDMs that come in to Canada. An alternator will not be able to keep up with the electrical demands of dead batteries along with those needed to run all the electrics in the vehicle.


~John

 

[JAC83]

Do you go mudding often? because at least in the 1FZ-FE engines, the alternator is a PITA because the brushes get all caked up with mud and stop working, they also wear down faster.

In our engines the first thing we try is rev up the engine and spray the alt with a water hose, if that doesn't work then you can try hitting it with a piece of wood (the handle of a hammer, for example) and sometimes that's enough to loosen them up(don't hit it too hard though), if that doesn't work then you have to take down the alt and tear it down to clean the brushes.

I know your engine is different, but the alternator is probably very similar, hope that helps.

 

[keving]

No I don't, this machine has been babied all its life, and has low mileage. Are these alternators internally or externally regulated? Ive had many regulators go in the past and hope this is the same issue. if they are externally regulated...where are the regulators?

 

[UpsideDown]

No I don't, this machine has been babied all its life, and has low mileage. Are these alternators internally or externally regulated? Ive had many regulators go in the past and hope this is the same issue. if they are externally regulated...where are the regulators?

As already stated in this thread, there are BOTH types of regulators commonly used in Land Cruiser alternators. The reg will be a black box on the right hand inner fender area if it's external. It will even have "voltage regulator" printed on it if it is still legible.

Mileage is irrelevant in a JDM. It could have sat in traffic for 10,000 hours and gone 50 kms. It's all about alternator load and engine hours.


If you still have JDM batteries, replace them.

DO NOT install AGM style batteries (eg: Optima) in a 24V truck.

~John

 

[_Walker_]

Has anyone figured out a practical solution to getting more power (IE larger alt) on these trucks yet? I know someone a while back was working on a rebuild kit that may be able to squeese a few more amps out but didn't hear anything after the fact....

 

[simonliew]

disconnect the batteries and just check the brushes on the truck.
Simon

 

[Radd Cruisers]

Has anyone figured out a practical solution to getting more power (IE larger alt) on these trucks yet? I know someone a while back was working on a rebuild kit that may be able to squeese a few more amps out but didn't hear anything after the fact....

Output is not really that big an issue with a 24V system. In my BJ42, the whopping 20A alternator was plenty even when I was the winch guy at the local poker runs (I might do 20 or 30 moderate pulls in an afternoon).

You must remember that 20A at 24V is comparable to about 45A at 12V (there is some advantage in the numbers due to 24V output - less heat generated, and generally longer duty cycles).

Diesels don't draw much of anything in the way of current to run the engine.

A gas engine can draw quite a few amps (10 to 15 or more) to fire the injectors, run the ignition coil, keep the computer alive etc.

Compared to...

A rotary pump diesel... a few milliamps to run the fuel shut down solenoid is all it takes.

This all adds up to an advantage in our favour.

Lots of people talk about wanting or needing more power, but the reality is that most do not need as much as they think.



Just some of my thoughts.

~John

 

[keving]

Why cant you use Optima batteries? I had them in it for a while last year till I swaped them into another vehicle

 

[_Walker_]

Well your probably right John, I haven't yet run into an undercharging issue with the 74 even when the hammer is dropping his mad beats, etc I just have concerns about adding a fridge, big radio (comms), more lights, rear winch etc...
however in all realism those are all things that arn't going to happen for a while...

HOWEVER; I recall last time I was in your shop you'd managed to track down some top notch good old fashioned flooded Lead Acid batts; whats a pair of your biggest set going for these days?
I think its about time to dump my optimas before they totally bite the dust,


on another note anyone want 2 slightly used D31 yellow tops? anyone.... anyone.... Bueller..... Bueller.....

and Keving, from another forum:

When the Swedes owned optima, they paid us well and quality was foremost of all at all cost. JCI is the company that KILLED optima batteries, we always had 99.99 pure lead until JCI bought optima. The first thing they did was: fired all of the on staff scientists, then fired all of the PHD's, then fired the chemists, then dismantled the chemistry lab, then dismantled the prototype lab, then got rid of the pure lead and replaced it with lead with higher tin content, then JCI brought in their genius engineers and re formulated the lead acid paste, then replaced the AGM paper with lower grade paper, ex cetera, ex cetera. All of this was done within the first 2 years of their ownership!

Iv also heard rumors of issues on 24V applications with these things but I have yet to hear a technical explanation of what EXACTLY is going on..
The other issue is if they ever get into an overcharging situation theres no way to refill the cells from boil off; and they cant be reconditioned like a good old fashiond plate style batt.

 

[jonb96150]

Why cant you use Optima batteries? I had them in it for a while last year till I swaped them into another vehicle

Yeah, what he said.

When I got my 24v 70 from Brett it had yellow tops in it, and still does. I've had it over two years and I don't know how long they were in there prior to that. I check the voltage with a meter on occasion and they have always been even. There is a "Solar" brand equalizer installed.

But I'm all ears if there have been issues. That quote re: JCI going way down on QA and R&D was interesting.