3B Voltage Regulator... (1 Viewer)

MrMoMo

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1984 BJ60, 12V

Ok. Replaced the diodes in the alternator about a year ago. Replaced the brushes as well. Also replaced the regulator (did reg & brushes before determining that it was diodes)

A few times over the past two months or so, my regulator has been over regulating - up to 16V at times. It wouldn't stay there, at idle it would be around 12.5, but at highway speeds it would sometimes go up as high as 16V - Not good for batteries or electronics.

So, I decided that before I toasted something, I would get a new regulator. Last one I got was from Toyota, at about $85CDN - it came as a Transpo IN218. It worked great for most of the year before it started doing this occasional over-regulate. Ordered the new one (from ASE supply online) Cost $38US shipped. Came as a Transpo IN218. Installed it last weekend and it seemed to be fine. Ran right about 13V - rock solid, Idle, full, anywhere in between. Yesterday It started not doing so well. Now I get 12V at idle, and maybe high 12's at anything above idle. (see pic for aproximate high)

So... did I just crap out and get a couple of dud regulators? or is there something causing my regulators to die that I am over looking? I don't want to just keep buying regulators if there is something else I should be looking at....

Thanks!
volt_reg.jpg
 
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Yesterday It started not doing so well. Now I get 12V at idle, and maybe high 12's at anything above idle. (see pic for aproximate high)

So... did I just crap out and get a couple of dud regulators?..
If your alternator was working hard, then I think "high 12's" may just be acceptable.

And the following may make your alternator "work hard":


  • A battery that is not fully-charged
  • A high current draw-off (headlights turned on or whatever)
So what I'm saying is that I wouldn't necessary assume your second solid-state regulator is faulty from those low voltage figures. (It depends!)

:cheers:

PS. Maybe leave your battery on a charger overnight and then do your voltage checks again without having anything like lights and heaters turned on. (See if you get a higher figure.)
 

MrMoMo

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Ok, so an update on this... yesterday after work (noon), I keyed on to glow and only got about 7 volts. (DOH) boosted the truck from Moosecruisers truck and drove home with the only electrical load being the wipers (and any engine acc/gauges etc) The whole drive home was just over 12V. Now I know something is wrong here. - A bad regulator would not kill the batteries. So, I think AGAIN, I have lost a diode. To verify this, I put my amp clamp on the alternator feed line, and it was flowing 300 - 600 mA with the engine off - so that is what killed my batteries. To verify this, I pulled the alternator lead off, and it sparked when I disconnected it. There should be NO arc there, as power should not be able to flow from the batteries back through the alternator to ground - unless a diode is blown.

SO.. pulling the alternator off the parts truck this morning... WHY is it always the coldest day when I have to do this?? (yesterday was +7°C, today it's -18°C!!!!!)

So, I guess the question now, is if there was a diode that was on it's way out, could it have caused the old regulator to OVER regulate sometimes?
 

MrMoMo

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If your alternator was working hard, then I think "high 12's" may just be acceptable. (See if you get a higher figure.)
I would agree, but I am getting low 12's with NO loads on - and it doesn't go up. (I see it as anything below 12.6, is not helping to charge the batteries - and I am below 12.6, no loads on) - I guess I may have mislead in my statement above. (that's why I put the picture up!!) Funny though, my charge light has not come on the whole time - so I guess the alternator is still putting out, just not what it should.
 

MrMoMo

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Sounds like something else...

How are you batteries, connections, grounds etc. ?

~John
Well, I would think they are un-changed since the old regulator - but I guess it wouldn't hurt to check them as well. (though now I know something funky is going on internally) I'm thinking I have a blown diode on the positive side that is not allowing full charge to come out, and a blown diode on the negative side, which drains my batteries when the truck is not running. Dejavu a year ago...:bang:
 
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Ok, so an update on this... yesterday after work (noon), I keyed on to glow and only got about 7 volts. (DOH) boosted the truck from Moosecruisers truck and drove home with the only electrical load being the wipers (and any engine acc/gauges etc) The whole drive home was just over 12V. Now I know something is wrong here. - A bad regulator would not kill the batteries. So, I think AGAIN, I have lost a diode. To verify this, I put my amp clamp on the alternator feed line, and it was flowing 300 - 600 mA with the engine off - so that is what killed my batteries. To verify this, I pulled the alternator lead off, and it sparked when I disconnected it. There should be NO arc there, as power should not be able to flow from the batteries back through the alternator to ground - unless a diode is blown.

SO.. pulling the alternator off the parts truck this morning... WHY is it always the coldest day when I have to do this?? (yesterday was +7°C, today it's -18°C!!!!!)

So, I guess the question now, is if there was a diode that was on it's way out, could it have caused the old regulator to OVER regulate sometimes?
I'm eager to hear the outcome. I have a similar issue with the FJ55 with the 3B. When I was having issues it seemed that the altenator had an internal short. Does that sound similar to your issues? An altenator guy here in Guatemala bandaided it but I want it right NOT "chapus" as they say here in Guatemala.
 
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Ok, so an update on this... yesterday after work (noon), I keyed on to glow and only got about 7 volts. (DOH) boosted the truck from Moosecruisers truck and drove home with the only electrical load being the wipers (and any engine acc/gauges etc) The whole drive home was just over 12V. Now I know something is wrong here. - A bad regulator would not kill the batteries........
So you admit here that have flat/low batteries!

And, as I said before, I think that when batteries need a lot of charging - they impose a big load on the alternator. So in this situation you get high current-output from your alternator but at lower voltage than normal because of the "lower-opposition-to-current-flow" (lower resistance) produced by a flat battery.

....So, I think AGAIN, I have lost a diode. To verify this, I put my amp clamp on the alternator feed line, and it was flowing 300 - 600 mA with the engine off - so that is what killed my batteries. To verify this, I pulled the alternator lead off, and it sparked when I disconnected it. There should be NO arc there, as power should not be able to flow from the batteries back through the alternator to ground - unless a diode is blown.

SO.. pulling the alternator off the parts truck this morning... WHY is it always the coldest day when I have to do this?? (yesterday was +7°C, today it's -18°C!!!!!)....
You clearly know what you're doing and I agree with the steps you're taking.

So once you have a good alternator there (that isn't flattenning your batteries when your vehicle is sitting unused) - Hopefully everything will be fine.

PS.....If you have a battery charger, I'd recommend recharging your batteries to both "help your replacement alternator" and "provide more starting current in the cold weather you have there".

...So, I guess the question now, is if there was a diode that was on it's way out, could it have caused the old regulator to OVER regulate sometimes?
I don't really know but I would suspect that a regulator MUST be faulty (no matter what) to allow a "16V charge" to occur.


Good luck.
:cheers:
 

MrMoMo

That's not rust, it's Canadian patina...
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So you admit here that have flat/low batteries!

And, as I said before, I think that when batteries need a lot of charging - they impose a big load on the alternator. So in this situation you get high current-output from your alternator but at lower voltage than normal because of the "lower-opposition-to-current-flow" (lower resistance) produced by a flat battery.
Yep, I totally get that - originally the batteries were not dead though, that only happened on the last day. V = I x R so if I goes up and R stays the same V must go down. (more amp flow at same resistance causes voltage to drop)

You clearly know what you're doing and I agree with the steps you're taking.
Well I hope I do! - I've been through a bad diode a few times, and I could understand the regulator going bad, just was a bit confused by the 2nd regulator not fixing the problem. Maybe the first regulator over-regulating fried one of the diodes?


So once you have a good alternator there (that isn't flattenning your batteries when your vehicle is sitting unused) - Hopefully everything will be fine.
Man you know I hope so!!

PS.....If you have a battery charger, I'd recommend recharging your batteries to both "help your replacement alternator" and "provide more starting current in the cold weather you have there".
Yep, I did that as soon as I disconnected the alternator, figured there was no point sitting around with dead batteries, and also no point in having the charger output drained to ground through the alternator.

I don't really know but I would suspect that a regulator MUST be faulty (no matter what) to allow a "16V charge" to occur.
Yup, that was my figuring too. It didn't do it all the time, so I'll keep it as an emergency back up.

Good luck.
:cheers:
Thanks! - Now if only I could get that stupid lower bolt out of the parts truck alternator!!! :bang::bang::bang:
 

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