HJ45 alternator concerns (1 Viewer)

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Jul 19, 2004
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Location
Richmond, CA
Hey team, I’m at the end of a complete clean up and replacement of wiring and connections for my basic electrical and starter system. Battery, starter, voltage regulator and almost all that wiring has been replaced.

My problem:
The battery isn’t getting fully recharged and on colder days that’s a challenge since I’m forced to start with glow plug warmup. I suspect it’s an intermittent issue with my alternator but I’m unclear how to test this. The truck has been almost daily driver and this is definitely more problematic on colder days. The truck is an HJ45 all stock. BTW glow plugs have not been changed out because they seem to work but maybe I need a little education on how to tell if they’re a cause of my problems.

Open to suggestions.

I’d like to take it to someone who can do a full load test and let me know how the alternator is performing so if you know someone in the Bay Area preferably East Bay.

Thanks in advance for any advice.
 
Symptomatically.. what are you actually seeing happen when a problem occurs?
 
Symptomatically.. what are you actually seeing happen when a problem occurs?
I drive the truck daily and can rely on a good start almost always but sometimes I have a less powerful start and usually when it’s a lower power turnover or better described as a labored start I can almost always expect it will fail to start. Then I’ve fully drained and can barely turn the engine over.

What I was reminded recently was that it almost always happens when it’s colder out, something like a 55 degree evening can result in a labored start and because I seldom need it, I typically don’t warm the glow plugs first. Recently, I tried to warm the plugs after attempting to start the truck and just didn’t have enough juice.

When I do have the truck running, I expect to see a charge on the battery that’s indicative of an alternator charging but even when I accelerate the rate of charge only changes from battery level to maybe .2 Volts more. Say 12.1 to 12.3 while accelerating, but I am expecting to see a higher charge voltage since the alternator is running.

My thoughts are that the alternator is doing something but not quite enough to keep a good charge especially when temps start to dip.

I could be way off and I’m happy to hear from you guys. BTW 12volt not 24v
 
I drive the truck daily and can rely on a good start almost always but sometimes I have a less powerful start and usually when it’s a lower power turnover or better described as a labored start I can almost always expect it will fail to start. Then I’ve fully drained and can barely turn the engine over.

What I was reminded recently was that it almost always happens when it’s colder out, something like a 55 degree evening can result in a labored start and because I seldom need it, I typically don’t warm the glow plugs first. Recently, I tried to warm the plugs after attempting to start the truck and just didn’t have enough juice.

When I do have the truck running, I expect to see a charge on the battery that’s indicative of an alternator charging but even when I accelerate the rate of charge only changes from battery level to maybe .2 Volts more. Say 12.1 to 12.3 while accelerating, but I am expecting to see a higher charge voltage since the alternator is running.

My thoughts are that the alternator is doing something but not quite enough to keep a good charge especially when temps start to dip.

I could be way off and I’m happy to hear from you guys. BTW 12volt not 24v


is your 12V alternator internally Regulated or Externally / Remote type ?



Photos would really help here alot .............fyi


of both your 12V alternator and your voltage regulator

especially the connection points / connectors / B+ ring-terminal etc .......
 
When I do have the truck running, I expect to see a charge on the battery that’s indicative of an alternator charging but even when I accelerate the rate of charge only changes from battery level to maybe .2 Volts more. Say 12.1 to 12.3 while accelerating, but I am expecting to see a higher charge voltage since the alternator is running.

Well thats definitely a fault.

I would invest the time to source a 2H internally regulated alternator and do the conversion - if its the factory alternator its likely well past its use by date (or soon will be). In the meantime, there's some tests you can do on your regulator..

1668319834728.jpeg


1668319852697.jpeg

I'd also confirm continuity between alternator output and regulator and regulator output and battery (I have a wiring diagram somewhere.. but cant find it at the moment)..
 
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I drive the truck daily and can rely on a good start almost always but sometimes I have a less powerful start and usually when it’s a lower power turnover or better described as a labored start I can almost always expect it will fail to start. Then I’ve fully drained and can barely turn the engine over.

What I was reminded recently was that it almost always happens when it’s colder out, something like a 55 degree evening can result in a labored start and because I seldom need it, I typically don’t warm the glow plugs first. Recently, I tried to warm the plugs after attempting to start the truck and just didn’t have enough juice.

When I do have the truck running, I expect to see a charge on the battery that’s indicative of an alternator charging but even when I accelerate the rate of charge only changes from battery level to maybe .2 Volts more. Say 12.1 to 12.3 while accelerating, but I am expecting to see a higher charge voltage since the alternator is running.

My thoughts are that the alternator is doing something but not quite enough to keep a good charge especially when temps start to dip.

I could be way off and I’m happy to hear from you guys. BTW 12volt not 24v
Well thats definitely a fault.

I would invest the time to source a 2H internally regulated alternator and do the conversion - its if the factory alternator its likely well past its use by date (or soon will be). In the meantime, there's some tests you can do on your regulator..

View attachment 3166563

View attachment 3166564
I'd also confirm continuity between alternator output and regulator and regulator output and battery (I have a wiring diagram somewhere.. but cant find it at the moment)..


by all means confirm and verify the present condition on both your 12V alternator and your EXTERNAL regulator too ..


IF .......

you find you have a faulty EXTERNAL Voltage Regulator or it's device side connector or wires are bad maybe ........


this LINK Below covers ALL 2H 12V External Voltage Regulators :






1668321008396.png



Supersedes ALL TOYOTA and Genuine NipponDenso Part's below :

IF you do NOT see your part # here or on the LINK page PM me , i have a complete and up-to-date supersession list from DENSO Japan ......



27700-13010 , 27700-13030 , 27700-22010 , 27700-24010 , 27700-31010 , 27700-33010 , 27700-36010 , 27700-36020 , 27700-38020 , 27700-15040 , 27700-41011 , 27700-13030 , 27700-44021 - 27700-13080 , 27700-13040 , 27700-44020

27700-15040 27700-15011, 27700-36010, 27700-36020, 27700-38130, 27700-13010, 27700-13030, 27700-22010, 27700-24010, 27700-31010, 27700-33010
27700-38020 27700-41011, 27700-15040







denso 1 - Copy (2).jpg
 
is your 12V alternator internally Regulated or Externally / Remote type ?



Photos would really help here alot .............fyi


of both your 12V alternator and your voltage regulator

especially the connection points / connectors / B+ ring-terminal etc .......
Externally. I’ll get some photos.
 
Well thats definitely a fault.

I would invest the time to source a 2H internally regulated alternator and do the conversion - if its the factory alternator its likely well past its use by date (or soon will be). In the meantime, there's some tests you can do on your regulator..

View attachment 3166563

View attachment 3166564
I'd also confirm continuity between alternator output and regulator and regulator output and battery (I have a wiring diagram somewhere.. but cant find it at the moment)..
Thanks for this attachment I will dig right in
 
Well thats definitely a fault.

I would invest the time to source a 2H internally regulated alternator and do the conversion - if its the factory alternator its likely well past its use by date (or soon will be). In the meantime, there's some tests you can do on your regulator..

View attachment 3166563

View attachment 3166564
I'd also confirm continuity between alternator output and regulator and regulator output and battery (I have a wiring diagram somewhere.. but cant find it at the moment)..
I quickly realized this is an aftermarket non-nippon denso regulator and so I’d have to study it a little to understand these contacts versus what I’ve got. I’m leaning towards simply buying the right part.
 
Externally. I’ll get some photos.
There are only fog lights added as accessories, 4 front and rear. All work. Not even a radio in the truck.

CB9D3B22-124E-436F-A586-D23031F9EED0.jpeg


AC7CCF04-BEE9-4458-9F1A-7377EF6FD2E6.jpeg


79B87424-3FC5-44C3-A0EA-71A1EF78879A.jpeg


4F48A50F-2B19-4110-A473-3C03F5A043B1.jpeg


D3C66374-C6B1-4C78-9335-53628D6601F4.jpeg
 
is your 12V alternator internally Regulated or Externally / Remote type ?



Photos would really help here alot .............fyi


of both your 12V alternator and your voltage regulator

especially the connection points / connectors / B+ ring-terminal etc ......
@ToyotaMatt looking through your site, I struggle to match something like the HJ45, I saw the FJ45 and saw several BJ options and HJ60. Now that I uploaded some photos if you have a suggestion how I decipher the correct part number that would be great.

Thanks
 
Externally. I’ll get some photos.


the AFTERMARKET external Regulator being ALL new and shiny is a RED FLAG of sorts .........
 
@ToyotaMatt looking through your site, I struggle to match something like the HJ45, I saw the FJ45 and saw several BJ options and HJ60. Now that I uploaded some photos if you have a suggestion how I decipher the correct part number that would be great.

Thanks


the LINK i posted ABOVE and here again covers ALL 12V volt 6 wire external NipponDenso Applications both USA Spec. and NON-USA Spec.


- BUT ....... / however

- i can indeed confirm it's correct , i would need your FRAME # and Modle ID code for your ENGINE BAY Aluminum DATA ID Plate .......

- , i DO see your Harness side plug connector has ONLY 6 wires , this is OK ........fyi

- i would STILL have your correct ALTERNATOR 12V manually Bench Tested also , for sure .......

LINK :



- if your 12V Alternator turns out to be faulty , there are OPTIONS on my table not listed in my online store , because i only have 1 of them / one-off items ......


- all below are 12V NEW DENSO / Genuine NipponDenso Varietees , again i would need more info on your current set-up if this route takes shape ?







1668388823740.png
 
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the AFTERMARKET external Regulator being ALL new and shiny is a RED FLAG of sorts .........
Yea it is for me as well but since it hasn’t always been a problem I had discounted it. Deleted something you’ve already answered @ToyotaMatt ill see about placard data and we can exchange details.

I’m not opposed to buying one.
 
Separate but similar topic, while scouring for info on this problem, I read that alternator replacement is not recommended because of the vacuum on the back of it being extra rare and hard to find. Do you sell an internally regulated alternator that supports this vacuum setup? @ToyotaMatt

Thx
 
Separate but similar topic, while scouring for info on this problem, I read that alternator replacement is not recommended because of the vacuum on the back of it being extra rare and hard to find. Do you sell an internally regulated alternator that supports this vacuum setup? @ToyotaMatt

Thx


if you look closley , the spines drive shafts stick out the back side

you would simply transfer over your current pump to the NEW UNIT ........
 
Great, wanted to make sure. Well that part number for the alternator is still legible. I’ll get it tested.
 
is your 12V alternator internally Regulated or Externally / Remote type ?



Photos would really help here alot .............fyi


of both your 12V alternator and your voltage regulator

especially the connection points / connectors / B+ ring-terminal etc .......
Some photos as I removed. I took it to a local alternator shop and they said they could not bench test it without the vacuum pump attached, is that true? I can’t see what the pump does for the alternator unless it holds the shaft centered. Then we discussed replacing brushes or inspecting them and he said he needs a special tool to disassemble it to check the brushes. Any truth?

What if I buy an alternator and regulator do you need the alternator core @ToyotaMatt ?

A9510B78-DD5B-464A-BDF4-C9606C02FBCF.jpeg


8D8B03A4-9FDD-4A94-BF7C-55325285AE73.jpeg


E6CC0A83-6D60-4A54-B55F-CE9E9D5FC141.jpeg
 
Some photos as I removed. I took it to a local alternator shop and they said they could not bench test it without the vacuum pump attached, is that true? I can’t see what the pump does for the alternator unless it holds the shaft centered. Then we discussed replacing brushes or inspecting them and he said he needs a special tool to disassemble it to check the brushes. Any truth?

What if I buy an alternator and regulator do you need the alternator core @ToyotaMatt ?

View attachment 3177107

View attachment 3177108

View attachment 3177109


We will talk about the CORE

I am flexible on that topic , we will discuss it further

The BIG topic is we match you up Correctly with the Correct Factory Fit Form and Function …


At the end of the day I would rather see u with a NOS reliable Genuine NipponDenso Unit ….

After all I generally only dabble in the NEW OLD STOCK topic

So cores come second , your correct unit that best meets your needs

Is my priority here ….
 
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