Hilux 4x4 Forum

Hi guys. Not my week!!!

So friday my battery light comes on on my way to work (I replaced my alternator about 6 months ago). The weekend I scratch around. I measure the 3 connector pins comming out of the alternator. They measure 0V, 0V and 3V. I look a bit further, and I see my voltage regulator is clearly burned out (my regulator isn't on the back of the alternator, it's a little box bolted to the side of my engine bay). I opened it up and could see the copper coil is covered with black stuff and I can smell something burned.

Anyway, so I gou to Autozone yesterday, I buy a new voltage regulator and put it in. Start the car, no more battery light on the dash. Half way to work this morning and the battery light is back on :evil:

So either the newish alternator IS faulty, or the voltage regulator burned out again, or the alternator burned out the regulator . . .

Any thoughts, advice ideas?

Thanks!!!!!!!!!!!!!!!!

Did you check if the regulator actually burned again? Did you measure the output of the pins after fitting the regulator? Just curious but no idea where to start looking. Not a sparky. If the reg burned again I would definitely suspect the alternator. The output should be in the region of 13 to 14 volts.

Hi

OK. So I opened up the new regulator, and I saw than in this one, the coils are covered in paper. But the one's paper is brown
Is that normal. Does that coil get warm that makes the paper brown? Or did it burn out again?

If it is burned out, then that new regulator only lasted 10 minutes :evil:

I also used a multimeter and measured the voltage comming from the alternator. It has 3 pins at the back.
I measured from each pin to the engine block and got 0V, 0V and 3V.

It is supposed to be a new alternator I put in end of last year

Must you not measure across the pins?

I don't know.

Anyone know?

I would not use a Midas brand. Especially components for altenator..... Try phoning around for a Bosch one.... Doubt that the price might be ridiculously high.

Hi

Two things there. I'm not sure you get those external voltage regulators in the Bosch brand.

Secondly, I've burned out two regulators, including my origeonal one that's been running fine for years. There must be something else wrong that's burning out the regulators . . .

Hi I hope that I don't add to your confusion rather than the solution but here is how I understand it. If you look at the three pins. The centre one (one on top that is at a different angle) with the wide lug is the one that supplies power to the stator in order for the alt to work. This must measure 12 volts on the plug when the ignition is switched on and will measure 0 on the lug as it is an input. One of the other two pins will measure 0 if the alternator is not working such as when the black wire is not connected and 12 when working correctly. This is the feed to the battery/charge light. The light goes off if there is current flowing over that pin. Not sure which of the blue or green ones?. The other (I think provides) input into the regulator to measure and be able to regulate the volts.

All the regulator does is allow current to flow from the alt to the battery when the voltage drops below a certain level (eg 12.5V) and cuts off the voltage when it becomes more than 14.5 V(normally) to protect the battery and other peripherals. Some of them regulate the input into the alternator to keep the voltage between the parameters. I suspect yours is the latter.

The coil on that regulator does look suspect to me. It seems as if it got hot. I am not sure if those coils are operated by the voltage directly from the alt or if they are operated by a dedicated circuit supplying power (i.e. through the fuse box). If directly from the alt it is possible that it could have blown. My thinking at least.

It is clear that it worked for years. The only thing that changed was the alternator. If the reg failed on its own the new one would have lasted for another couple of years. (Assuming there was nothing wrong with the new reg). This would point to the alternator.

You have one of two options. Just replace the reg on the asussmption that it was a faulty unit and risk it burning again. Could be the cheapest option but if it burns again then obviously not. The alternative is to have the alternator seen to or replaced and then check what is happening. The reg could still be working or it could be buggered and you will end up buying another one again.

Hope someone more knowledgeable chimes in here

Marnus your logic makes a lot of sense...

ThysdJ wrote:Marnus your logic makes a lot of sense...

Well, that seems like an old technology regulator, what was known as a "vibration" regulator, the reason being that the one relay is opening/closing quite fast to regulate the voltage by means of making/breaking the field current (I think!!). Some regulators also did current limiting, which modern regulators don't do AFAIK. Didn't even know that Hiluxes had them.

It is an electro mechanical device with a limited lifespan (again I can be wrong but that was my impression when I still had vehicles that used them: VW Beetle, 1973 LC). The problem is that the contacts of the relay burns away because it's breaking a field current, which has a lot of stored energy. (High inductance). The contacts can also fuse together, don't know what the symptoms are then?

If it was mine, I'll try and get a replacement Bosch, identify wire coming from ignition via battery charge globe and connect, put nice thickish wire from alternator output to starter/battery, problem solved, then you only replace bearings, and regulator when brushhes are worn (you can even just get new brushes and solder them in).

The other problem that you maybe have is that you bought from Autozone, some of their products are Spyrex (Made in China), so I wouldn't trust it. (But that's just me....)

I don't know if you can even still find auto electricians that will know how that voltage reg works, or how to check it. (I know how to test a Bosch one, but not the relay one).

Cheers,

C

Hi guys

So I don't understand a lot of what you guys are saying, but like I said. I have the import model Hilux and I have a Japanese alternator where the regulator is a separate box. You don't get those in Bosch. Also, I don't know how the Bosch type alernators work, but I think they have 2 pins at the back where mine has 3. Also, mine for some reason has to kick out 7.5V on the one connector. Not 12.something like the bosch ones. The Bosch ones kick out 12V AFTER it goes through the regulator. That is where you guys measure. Mine should measure 7.5V comming out of the alternator going TO the regulator. It seems to be quite the different setup from the newer Bosch type ones.

Anyway.

So I went to the auto electrician today. While I was waiting for him, I opened up the bonnet so long . . . opened up the regulator . . . was busy looking for my first burnt out regulator when he walked up. He took one look at the regulator without me saying a word and he told me my alternator is bust. So I told him exactly what has been happening and he starts talking about it being the stator or diodes (and that’s where he lost me).

So I went home and google’d a bit. Then I took the alternator appart. The I dug out my old alternator that stopped working after being exposed to too much mud at Kwaggaskloof. I took that appart completely, washed it out good, and could then clearly see that the diodes in the new alternator is burned out.

This is my old alternator washed out: This is my new alternator where you can clearly see the burnt out diodes. It's a but dirty, but you can see the diodes popping out of the holes. Mike's Place just said sorry. You get 1 day warranty. If it worked then it worked. And it was a new alternator I bought from them, not a secondhand one :evil:

Anyway, so with my old alternator cleaned out good, I'm going to take it in for testing tomorrow. I have a battery charger now, so I can take my time now sorting everything out properly. Last year I didn't and had to buy a new alternator asap when my first one failed.

Will let you guys know.

Stephan I'm glad there's light at the end of the tunnel, just wondering if replacing the alternator with a new Bosch one would be 1. an option and 2. be possible, then you know it's out of the way for many years. Just my 2cw

Donkey wrote:Stephan I'm glad there's light at the end of the tunnel, just wondering if replacing the alternator with a new Bosch one would be 1. an option and 2. be possible, then you know it's out of the way for many years. Just my 2cw

I am busy thinking the exact same thing. And yes, it is possible I think.

But it depends. If my old alternator works now, then it's just R190 to buy a new regulator. If it's not, then yes, I'll buy a whole new bosch alternator.

My next question, and I'm busy starting a new thread for this, is will that alternator be enough for a dual battery system with an fridge in the back?

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Stephan,

Just make sure the old alternator wires are firmly soldered. From the pic you posted, it almost looks as if the wire from the top left diode is loose, but that can be a photographic thingie.





-F_D

Hi Stephan

My Lux is an 1989 import model,and that is how its altornator look

Stephan, contact me... may have a genuine Bosch 90amp for you, for a small fee of course....

Oi.

Things were looking very good for a second there, but I'm going down hill again.

Recap: I took the old alternator that got killed by the mud to get tested. It's not generating a field. The stator is burned out.

The new alternator's solonoids are burned out.

I put the new alternator's stator in the old one and built a working one from the two faulty ones. Took it to the auto electrcian. He put it on a bench, and it tested fine.

So back home, I put it in, and I burn out the 60amp fuse, and one more and one more . . . But if I leave the newly built alternator and regulator plugged out, then the fuse doesn't burn out

Somewhere I've got a new problem . . . :alvarin:

Chuck that old jap crap and fit the 90A bosch mr B has.

The jap ones work fine, but chuck it out once it starts giving trouble.

The pic Dawie posted is a bosch, but it looks like a 45A, they were fitted to most locally manufactured Hiluxes.

Been trying to call Mr B all week, but I only get voicemail . . . :alvarin:

Hoppy wrote:Chuck that old jap crap and fit the 90A bosch mr B has.

The jap ones work fine, but chuck it out once it starts giving trouble.

The pic Dawie posted is a bosch, but it looks like a 45A, they were fitted to most locally manufactured Hiluxes.

Was 45A rewired to 90A

I won! I won!

Take that you alternator you

Just hope it stays fixed and I don't burn out another regulator in a day or 2

Glad you got it sorted and some good lessons learnt in the process.

Jip

And the battery light is still off, so I coinsider this sorted

What was the final remedy?

Boland4x4 wrote:What was the final remedy?

My last issue with the shorting was just a wiring problem.

My alternator has 4 wires connecting at the back. Earth, neutral, field, and battery. I thought that that last seperate wire that gets connected at the back of the alternator to the bolt with a nut was earth, or that was what I was told. But it was actually the wire comming FROM the battery . . . the live wire . . .

What function does the rectangular black boxie with lead perform?

It's a suppressor capacitor to reduce interference with radios and other sensitive electronics.

Thanks!