For Sale Glow Pre-Heating Timer, 24V, for HJ61 with 12HT engine (10/1985-12/1989) (1 Viewer)

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Joined
Sep 28, 2002
Threads
559
Messages
8,112
Location
Kamloops, BC Canada
Website
www.shopraddcruisers.ca
Location
United States
Part number: 28521-68060.

Suitable for HJ61, 10/1985-12/1989, with 12HT engine.

Was fully functional when removed from a 24V HJ61.

Asking $250 USD. Shipping extra.

Located in Victoria, BC.

All parts are sold ‘as-is’.

Email for faster service at: raddcruisers [at] gmail [dot] com

Glow Pre-Heating Timer 12HT engine.png


Glow Pre-Heating Timer 12HT engine 2.png
 
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Hello, does the pre heating timer affect a delay in the alternator charging the batteries in cold starts?
Does it affect charging?

Yes, of course it will.

In cold weather, depending on how cold your area is, the glow system may run for up to a couple of minutes. The exact time can be seen if you look at the time vs temperature chart in the engine manual for the glow timer.

What you will see when the glow system is on is a pretty substantial drop in the system voltage that is well below 28V.

Things to check: alternator brushes - much like starter contacts, these are a replaceable wear item. If you have not checked them - ever - then do it right now - and also check your starter solenoid contacts at the same time and replace them if there is more than a slight amount of wear.

Also, you need to have healthy Group 27 batteries at least. Group 24s commonly recommended are too small for truly cold starts. I'd strongly advise against running AGM batteries in these vehicles as the charge voltage and rate is not correct and they won't last very long.

~John
 
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Does it affect charging?

Yes, of course it will.

In cold weather, depending on how cold your area is, the glow system may run for up to a couple of minutes. The exact time can be seen if you look at the time vs temperature chart in the engine manual for the glow timer.

What you will see when the glow system is on is a pretty substantial drop in the system voltage that is well below 28V.

Things to check: alternator brushes - much like starter contacts, these are a replaceable wear item. If you. have not checked them - ever - then do it right now - and also check your starter solenoid contacts at the same time and replace them if there is more than a slight amount of wear.

Also, you need to have healthy Group 27 batteries at least. Group 24s commonly recommended are too small for truly cold starts. I'd strongly advise against running AGM batteries in these vehicles as the charge voltage and rate is not correct and they won't last very long.

~John
 
The truck starts every time with no hiccups. It’s doesn’t get much colder than 40deg Fahrenheit where I live. But I notice it takes a few minutes after driving when the alternator kicks in and starts charging the batteries. It only does this after it’s been sitting for a few hours but not much in warmer days. It’s been doing this for as long as I can remember. I’ve had her since 2015.


For Context: 87 hj61 24 volt
Rebuilt alternator in last 15k miles
New external regulator
2 new non AGM batteries

I checked both positive and negative grounds

To do:
I’ll check the starter solenoid contacts like you suggested.
Perhaps a replacement pre heat glow timer relay?
 
The truck starts every time with no hiccups. [....] It’s been doing this for as long as I can remember. I’ve had her since 2015.


For Context: 87 hj61 24 volt
Rebuilt alternator in last 15k miles
New external regulator
2 new non AGM batteries

I checked both positive and negative grounds

To do:
I’ll check the starter solenoid contacts like you suggested.
Perhaps a replacement pre heat glow timer relay?
This is normal operation.

Check your Engine FSM to see how long the glow system runs for. It's quite long - you will see a substantial drop in charging voltage when it's running for the first few minutes. It will be well below 28V (charging voltage) and can get really low - if you're not used to how much current the glow screen draws.

My advice is to stop staring at the volts gauge... obessessing over certain things, because it caught your eye one day, can get really expensive, and needlessly so.

The starter won't affect charging voltage in this vehicle, but it's a very, very good item to check for maintenance.... because it's expensive to replace, yet very affordable to maintain, and that's why I mentioned it.

Replacing the glow timer won't affect the glow time - it's either working, or it's not working. The temp sender to the glow timer might have some effect, but it sounds like your system is working fine.


~John

PS
there are 2 different alternators installed in 24V HJ61s. A 30A or a 40A unit. This is plenty for this vehicle if you're not running zillions of electron sucking gadgets, but a large draw like the glow screen on a small-ish alternator will seem like it's too much, but really you're fine. There are very, very few constant loads on the electrical system of a fully non-electronic diesel... no ignition coils, no fuel pumps, no ECUs and so on.

PPS
If you're installing accessories, try to get items that run natively in 24V rather than using inefficient voltage converters. Most items can be had in multi-volt or 24V .
 
This is normal operation.

Check your Engine FSM to see how long the glow system runs for. It's quite long - you will see a substantial drop in charging voltage when it's running for the first few minutes. It will be well below 28V (charging voltage) and can get really low - if you're not used to how much current the glow screen draws.

My advice is to stop staring at the volts gauge... obessessing over certain things, because it caught your eye one day, can get really expensive, and needlessly so.

The starter won't affect charging voltage in this vehicle, but it's a very, very good item to check for maintenance.... because it's expensive to replace, yet very affordable to maintain, and that's why I mentioned it.

Replacing the glow timer won't affect the glow time - it's either working, or it's not working. The temp sender to the glow timer might have some effect, but it sounds like your system is working fine.


~John

PS
there are 2 different alternators installed in 24V HJ61s. A 30A or a 40A unit. This is plenty for this vehicle if you're not running zillions of electron sucking gadgets, but a large draw like the glow screen on a small-ish alternator will seem like it's too much, but really you're fine. There are very, very few constant loads on the electrical system of a fully non-electronic diesel... no ignition coils, no fuel pumps, no ECUs and so on.

PPS
If you're installing accessories, try to get items that run natively in 24V rather than using inefficient voltage converters. Most items can be had in multi-volt or 24V .
You’re spot on! I stare at the voltage like it’s the stock market. Yea I have found myself going down the rabbit hole the past couple weeks. It’s working fine once it’s warmed up. I’ll heed your advice and address other maintenance stuff like the starter…

Thank you!
Rey
 
Hola que tal, el mio es un Hj61, 12HT,
Ahora le montó un alternador con regulador interior.
IMG20230120134511.jpg

ahora que ha venido el frio aquí en España, me pasa lo mismo que al primer arranque el voltímetro del tablero baja a 16v y no sube a 27'5 Voltios hasta 2 mimutos después... Y ahora viendo este post y otros de los fusibles Links, estoy ya dudando del problema que tienes, que yo no veo normal ésto!!

Que al arrancar ya tendria que producir 28Voltios no?
METROha roto hasta la ràdio que la tengo a 12v.

Me ocurre lo mismo que el link de aquí abajo, se me queda fija la Luz amarilla del Turbo , y en altas revoluciones y baches algún día ha funcionado la luz Verde del Turbo!

 
Hola que tal, el mio es un Hj61, 12HT,
Ahora le montó un alternador con regulador interior.
View attachment 3225521
ahora que ha venido el frio aquí en España, me pasa lo mismo que al primer arranque el voltímetro del tablero baja a 16v y no sube a 27'5 Voltios hasta 2 mimutos después... Y ahora viendo este post y otros de los fusibles Links, estoy ya dudando del problema que tienes, que yo no veo normal ésto!!

Que al arrancar ya tendria que producir 28Voltios no?
METROha roto hasta la ràdio que la tengo a 12v.

Me ocurre lo mismo que el link de aquí abajo, se me queda fija la Luz amarilla del Turbo , y en altas revoluciones y baches algún día ha funcionado la luz Verde del Turbo!

Google translate helped with what I did not understand from my weak Spanish:

"Hello how are you, mine is an Hj61, 12HT,
Now he installed an alternator with an internal regulator.

now that the cold has come here in Spain, the same thing happens to me that at the first start the voltmeter on the dashboard drops to 16v and does not go up to 27.5 Volts until 2 minutes later... And now seeing this post and others about the fuses Links, I'm already doubting the problem you have, I don't see this as normal!!

That when starting it would already have to produce 28Volts, right?
M has even broken the radio that I have at 12v.

The same thing as the link below happens to me, the yellow Turbo Light stays fixed, and at high revs and potholes the Green Turbo light has worked one day!"


==============

Part II from the thread located at:


Hola que tal, me ocurre el mismo fallo de las luces del tacómetro del turbo, se queda la naranja fija, y ahora que hace frío el primer arranque no carga el alternador hasta pasados unos 2 minutos aproximadamente.

NO cambió ningún enlace de fusible nunca. Solo lleva uno creo en la salida del positivo de batería, de mi Hj 61.

Los reles no sé donde los lleva ni que funcion hacen al dar el contacto.🤔

Voy perdido con este fallo, he puesto otro el alternador y hace lo mismos!🥴

============
Preamble & Caveat:

I will start by saying that doing this kind of diagnosis is my business, and I don't even have time to reply to my business emails let alone have time to reply to these. Howver, I will do my best to be of help. I do not like diagnosing - rather - blindly chasing other peoples' problems - from afar. Long distance diagnosis is fraught with all kinds of problems.

Perhaps @OGBeno can relocate this thread as appropriate because it shoud not be in the JDM/diesel parts for sale section.

My replies:

Part 1 -

The voltage dropping to 16-ish Volts on the semi-accurate dash gauge during the glow period is normal. I will repeat this is NORMAL operation for this system.

Once the glow screen turns off, the voltage will recover as the batteries recover from the drain from cranking and glowing.

Fusible links are no longer in production for the HJ61. However, using the Factory Toyota electrical diagrams you can make your own fusible links using fusible link wire using the wire diameter listed in the wiring diagram. The wire size is listed in square mm, and not gauge size. Use a length about 4" or 10cm long of the correct wire size, add appropriate terminals and put it into place.


==========

Part 2 -

The OP (original poster) in the linked thread has a problem that most likely lies in the voltage regulator of his alternator.

Over-charging is almost always related to a bad voltage regulator.

But it could be related to other things, but the Occam's diagnosis track is to look for the most obvious things with the most obvious explanation first. If it was working perfectly well and then something suddenly changed, then look in the obvious places first - voltage regulator, diodes.

If the weather was unusually wet or road salt was applied (and it was wet or snowy - to create an electrolyte) check your main electrical connections and fuses/fusible links. However, a broken wire will much more likley cause zero volts than too many......

The other thing I would do is a charging system analysis and see if there is one or more failed diodes in the alternator.

Failed diodes usually show up as lower charging and running voltage, poor or almost absent recharging of the batteries, and batteries that go flat from improper charging over a period of hours (or driving time) to a few days of driving time. The alternator will also not be able to carry the load of accessories (blower fan) and headlights and these will run off what's left of the batteries. The dash volt gauge will show that the alternator is not responding to the accessory load by showing a drop in voltage (instead of maintaining voltage) and then it will show a slow drain below 24V over time as the batteries begin to die.

With failed diodes the alternator is unable to produce both the voltage and current needed to recharge the batteries. Damage to the batteries and possibly some sensitive electronics is possible (there is not much of this in an old skool Land Cruiser, thankfully) as there is to too much AC ripple appearing in the circuit (because of the failed diode(s)). [hint: alternators produce 3-phase AC output that is converted into DC by a diode trio].

Now, as for the idiot lights on the dashboard. This can also be caused by a improperly or non-functioning alternator as the signal that the engine is running is not present (usually from a failed regulator).

There is a relay in the kick panel (driver's side, usually) that controls the signal going to these lights. Its function is to "know" whether the engine is running, or not - and this signal is provided by the alernator - and turn on or off the idiot lights on the dash via the electrical output from the alternator (via the voltage regulator). The "idiot lights" in this case are the lights that illuminate when the key is put into the "on" position (KOEO position).

These relays can have problems as they age with solder connections breaking (vibration, age, water contamination etc.) and can sometimes be repaired be re-heating and re-melting the solder to repair the connection. These relays are also out of production, and you would have to find a good used item or repair your own relay.

Also, it should be noted that the 24V HJ61s tended to have either a 30A or a 40A alternator. From the JDMs we have in Canada, the 30A alternators were typically found with external voltage regulators and the 40A alterntaors had internal regulators.


Hope this helps.


~John

 
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dear all,

it is the after glow which cause the drop of voltage when the engine starts to turn. even when it is plus 20 degrees.
it is a made to heat up intake air to have better emmision value, but it seriously demands battery and generator (when not new)
The afterglow is not required for cold starts in normal temperature area (not feezing cold).

Solution if you do not want this take pin 5 out of the connector and the afterglow screens are not activated
 
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dear all it is the after glow which cause the drop of voltage when de temp is not below freezing.
it is a made to heat up intake air to have better emmsioon value, but it seriously demands battery and genartor (when not new)
Take pin 5 out of the connector and the problem is solved.
The afterglow is not required for cold starts in normal temperture arear.
The after glow is to provide for smoother running after initial start-up and reduce emissions while the engine is warming up.

Where I live, we can get down to -32C or lower, and it's hard enough starting at these temperatures even with the glow functioning properly, and after glow is absolutely required.

There is no good reason to disconnect this function unless you're in an area with substantially warm temperatures all the time.

~John
 
The after glow is to provide for smoother running after initial start-up and reduce emissions while the engine is warming up.

Where I live, we can get down to -32C or lower, and it's hard enough starting at these temperatures even with the glow functioning properly, and after glow is absolutely required.

There is no good reason to disconnect this function unless you're in an area with substantially warm temperatures all the time.

~John
Correct
Like I said in normal temperature areas (mid europe and below)afterglow is NOT required and draws more current than pre-heat.
it uses both heat screens and it is always "active" as soon engine starts turning. it ;
The pre heat cold start.(use only 1 heat screen) is temperature controlled and kicks in before starting (glow light on)
Why 1 heat screen ? because when you use both before starting it drains the ,already very cold, battery much more wich could result in possible no start of startermotor

Direct injection engines like these should not have huge start problems in cold wether, it could be compression got more low or injectors need to be overhauled and or diesel pump.

But yes for sure it will make the engine run more smooth when the afterglow is on on these very low tempertures. thats a fact.
This is why I installed a webasto dieselheater in my hj61 controlled by phone.
send a message half hour before i want go and the car is warm and engine coolant also. this is a much better way to "pre-heat"your engine ;)
 
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El resplandor posterior es para proporcionar un funcionamiento más suave después del arranque inicial y reducir las emisiones mientras el motor se está calentando.

Donde vivo, podemos bajar a -32C o menos, y es bastante difícil comenzar a estas temperaturas incluso con el brillo funcionando correctamente, y después del brillo es absolutamente necesario.

No hay una buena razón para desconectar esta función a menos que esté en un área con temperaturas sustancialmente cálidas todo el tiempo.

~


Gracias a vosotros estoy aprendiendo mucho sobre estos pedazos de camiones!

Si que esto de el consumo de batería después de arrancar lo ha empezado a hacer ahora que hace 0° de temperatura 🥶, y ya el relenti ha cambiado muchos el sonido de tractor 🙊

Entonces ahora que ya se que este consumo de energia es normal no me voy a preocupar por eso y voy a reparar y sustituir los fusibles link que he encontrado en mal estado y aver si se arregla las luces de presión del Turbo 🐌!

Garcias Compañeros y a la que pueda subiré fotos y vídeos de cómo va quedando
 

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