HJ61 Charging troubleshooting and ideas needed (3 Viewers)

[opalbeetle]

Hello all,

I have a 1989 HJ61 that I am having some issues with when it comes to charging. I am new to the charging system of the truck, and I have read and re-read many of the threads here, online troublshooting manuals, my manual and I cannot track down what the issue might be.

Some history about the problem. I checked the brushes in the alternator of the truck to see what the wear looked liked on them. It turns out that they would need replacing but would be good enough to drive until the replacements arrived. So, I put them back in and somehow created a dead short that burnt the fusible link.

When I went searching for parts, I decided that I would get a new alternator and install it, just in case there were problems with the old one. I figured I could have the old one rebuilt as a spare if it had any damage. So, the alternator is in and now it's not charging at the correct amount of volts.

This is what I know:
This alternator has an external regulator
The dash lights are all on
All of the fuses are fine
It's charging at 24.7 volts at the batteries. I also checked from "B" on the alternator and it reads the same. The voltage increases with rpms and reduces as it returns to idle (no load like lights, heater fan etc.)
The voltage regulator does not appear to be doing anything - I have the original and a known good spare - neither of them seem to be "activated" at all (I'm not sure if this is the right word), I read somewhere here that the "F" pin on the regulator needed to have a 24v signal, it does NOT, so what does this mean?
I have replaced the fusible link and checked for continuity and all is good at that harness.
I put brand new batteries in the night before this all happened.

I am stumped and wondering what I need to look at next. So, some questions:
There is a plastic connector that comes off the alternator, are there voltage measurements that I can check there?
I've read about a charge relay, but the charging diagrams don't have one in the schematic. Does this mean that I don's have one or am I missing something?
Is the possibility of a bad, new alternator real?
Is it possible the batteries are done? (I don't have a load tester to see what's what, though I could borrow/buy if need be - one can never have too many tools.)

Any thoughts, insight, ideas and magical cures are welcome as I am out of ideas.

Thanks for your time on this!

Todd
near Winnipeg, MB, Canada

 

[sved]

Voltage should read about 27 volt when charging
Check your amps with a multimeter.That will tell you more

 

[opalbeetle]

Will do.

 

[sved]

Is it a JDM HJ61?
As far as i know '89 Hj61 had the alternator with the internal ic regulator(just like mine 87 hj60 and 88 hj61).So this external regulator can't be original.If the original one with internal ic regulator has been swapped with the one you have now,then there should be a charge relay in the right footwell behind the plastic cover.Its black and square and even reads Charge relay.
What do you mean with dashlights are on? Charge and filter?

 

[opalbeetle]

All of the lights are on. The turbo light, the locker lights, and the transmission light by the shifter. When I turn the truck to "on", the "charge" light is not on, nor does it come on when the truck is running.

As for a factory external regulator, it looks pretty stock to me. The wiring harness and 6 spade conncetor is all all there as are the threaded bolt holes to mount the regulator on the inner fender. The part number for the external regulator is 27700-57090. I will dig around and look for that relay again tonight when I am home from work.

 

[opalbeetle]

And yes, it is a JDM Hj61.

 

[sved]

Alright, the EPC shows that the regulator is original for a HJ61 with 24v 30A alternator.Learned something today .
The charge relay has partnumber 27790-57010.I doubt you will find it in your hj61 though.
I put my money on the ignition main relay .Should be sitting somewhere under the dash at your right side on a plastic relay block.partnumber 90987-02005.The relay contacts activate the charge light.Relay on means charge light on.

 

[HJ61 12HT]

If it is externally regulated, some circuits require the instrument panel charge bulb to be working to allow the regulator to do its thing, probably a good idea to check the charge bulb is not blown.

I've never seen an externally regulated HJ61.

 

[sved]

The EPC for Japan market shows this.

JDM HJ61 with a 30A alternator have a external regulator
JDM HJ61 with a 40A alternator have a internal(IC) regulator.

The wiring diagram for a external regulated generator doesn't show a charge relay.On the other hand the EPC says its there..
Lets see what opalbeetle can discover for us .....

If it is externally regulated, some circuits require the instrument panel charge bulb to be working to allow the regulator to do its thing, probably a good idea to check the charge bulb is not blown.

I've never seen an externally regulated HJ61.

That is correct for a internal regulated alternator.The external regulated has a different diagram.

 

[opalbeetle]

Well, lots of learning in here. I will look tonight to address the advice from above. I will most definitely report back with the findings.

What does EPC stand for?

 

[sved]

EPC = Electronic Parts Catalog

 

[opalbeetle]

Alright, so I removed the Ignition Main Relay and did the following tests on it. There is no continuity across 1 and 3 like it suggests it should have. So, I am assuming that the relay is shot! So, if the relay is done, I'm assuming that the voltage regulator isn't receiving any voltage and therefore doing its job!

So, does anyone know if these relays can be repaired or should they just be replaced?

For the record, there is NOT a Charge Light Relay in this truck.

 

[opalbeetle]

That should have said....therefore NOT doing it's job! (I'm not sure how to edit a post)

 

[sved]

Just replace the relay ,don't bother repair it.

 

[opalbeetle]

Alright, part ordered and it arrives tomorrow. I will let you know if it's the solution!

 

[opalbeetle]

Well, that wasn't the problem. I have exactly the same symptoms as before. I even checked the charge bulb to see if it was burnt. It was not. I checked the amperage of the alternator and it reads 10.9A - 11.0A at idle and as the rpms increase to 2000, the amperage climbs to ~15A. The voltage at idle remains at 25.3V and that's measuring right off the alternator (though it's the same across the batteries). I am completely stumped, as my knowledge of how this impacts the system is somewhat limited.

My question would be, what is this telling me?

 

[sved]

The amp should not rise if you increase the rpm, without load on the generator.With load it can rise to 15amp.
Voltage at idle is still to low,should be around 27-29 volt.

I'm still not convinced your regulator works like it should.

 

[opalbeetle]

I'm gonna back up and go through everything from the start again. I know the the alternator is a brand new, not rebuilt, Toyota part. So, Im gonna retrace steps and check connections, wiring, fuses etc. (again, cuz I've already done that) and double check the regulator. Gotta say, even though this was really MY fault, I have certainly been less frustrated about solving problems with cars.

Thanks for the advice and input, it's been most helpful and my learning continues up the curve!

 

[sved]

Truck starts normal ? Battery's give enough power to the starter motor? I mean ,does the alternator really charge up the battery's?

 

[opalbeetle]

Yup, the truck starts right up no problem at all. It appears to charge the batteries, though I wonder if there might be a problem with the batteries after the dead short. Maybe they aren't taking a charge.....hmmm. I thought I checked that, but I will add it to the list to recheck.