24 volt start 12 run

[Radd Cruisers]

I currently do not have a chassis manual for the HDJ81, I could probably work out the 12 to 24 volt run system, but it anyone has the schematic it would help things move ahead faster.

After reading the engine manual, it seems the system is much more complicated than I first thought.

-Voltage converter timer
-Voltage converter relay
-Starter relay

After sitting down and drawing this out I relized the 12 volt system must be shut down and seperated from the 24 volt system, not a easy feet or am I missing somethihg?

Thanks
Rob

 

[Greg_B]

Somewhere in Mud is an install write-up of a 13BT into an FJ40 on the eastern seaboard. He found a marine series/parallel switch which allowed him to run 24V start and 12V run.

hth's

gb

 

[nickw]

Hello Rob,

After my starter burnt, I was worried it got so hot it might of hurt something else on the system. I spent a number of hours figuring out how the series/parallel switch works and how it was all wired together.

If you want I can call you a discuss what I learnt with you.

Cheers,
Nick

 

[Radd Cruisers]

Thanks Greg, I have seen the magnetic switch and the wiring diagram, pretty simple and effective. Only draw back is the fact you can use a alternator with not much more than 60 Amps.

After that amperage you have to purchase a heavey duty unit for big rigs.

I would really like to use the toyota unit the customer purchased off a HDJ81, my electrical guy complemented the unit and said it was of the highest quality and encourage me to find the schematic and use it.

Somewhere in Mud is an install write-up of a 13BT into an FJ40 on the eastern seaboard. He found a marine series/parallel switch which allowed him to run 24V start and 12V run.

hth's

gb

 

[Radd Cruisers]

Thanks Nic, that would be great, a detailed description including the posts on the factory 81 and where the wires go.


I know the theory and may be able to funble through it, but I would hate to fry Toyota unit.

Rob

Hello Rob,

After my starter burnt, I was worried it got so hot it might of hurt something else on the system. I spent a number of hours figuring out how the series/parallel switch works and how it was all wired together.

If you want I can call you a discuss what I learnt with you.

Cheers,
Nick

 

[wussyPup]

Rob, you got mail.

BTW, you missed some excitement Sunday near Shawnigan - Island Rock Crawlers - Sunday Run

 

[Radd Cruisers]

Thanks for sending that information, good to have people like you on this board helping out.

Maybe I will catch up with you on another run, looks like fun.....

Rob

Rob, you got mail.

BTW, you missed some excitement Sunday near Shawnigan - Island Rock Crawlers - Sunday Run

 

[Greg_B]

I would really like to use the toyota unit the customer purchased off a HDJ81, my electrical guy complemented the unit and said it was of the highest quality and encourage me to find the schematic and use it.

Ahhh, cool. I should have clued in from your wording in the 1st post that you had the OEM series/parallel switch and were looking to use it. Glad you got it figured.

gb

 

[Radd Cruisers]

Ya the schematic was not as helpfull as they do not have the same markings that are the poles of the Denso switch.

Hopefully with some diagrams I can figure it out, the more you look at the marine schematics and the toyota the more you see the way the current flows and it kinda makes sense.

Will find out later this week.

Working on the 5PSI shut down switch wiring on the engine at this point.

Rob

 

[Radd Cruisers]

Todays verdict, not sure its worth the time and effort.

For instance, my customers 1HZ that is switched to a 12 volt system and start work just fine and that think is hovering around 600PSI.

No the 1HD-T has lower compression and would not have a problem running the twelved volt system.

In all the sytem is not that difficult, but there are some obstacles, somehow I have to islate the twevle volt side on one battery on start up if I am to use the Denso relay.This would allow both batteries to be used in the vehicle run position.

If I went with the GM/Marine unit for 160.00 rebuilt I could easily run it triclkes a charge back to sthe second battery which would be isolated from the twelve volt run. The second battery would be for start up only.

Does this make sense?

Rob

 

[nickw]

Hello Rob,

Sorry I have not called yet.
I have been working late latley.
I am even working right now.
Freak its 12:45 am.

I got to go home and sleep. Started at 8am this morning.
And people say us computer geeks don't work hard...

Anyways, if you still need help I can call you tomorrow night.
I will be working. but I could use the break.

Cheers,
Nick

 

[Icky]

Rob:

Something you might want to consider would be to run a 12-volt starter. The diesel mini-truck (08/83-08/87) 2LT starter is the same as the 1HDT (Part #28100-54090-84) except it is 12-volt.

You can eliminate your entire 24 to 12 switching issue as it is the only 24-volt part on the engine. They are available as a -84 Toyota factory remanufacture in the U.S. They bolt right in to the HDT starter nose. Considerable savings over a new one; in fact, I don't think you can buy a new one in the U.S., only the rebuild.

I've been running this setup on my HDJ60 conversion for almost 10 years in a cold climate with no headaches.

 

[Kalawang]

I currently do not have a chassis manual for the HDJ81, I could probably work out the 12 to 24 volt run system, but it anyone has the schematic it would help things move ahead faster.

After reading the engine manual, it seems the system is much more complicated than I first thought.

-Voltage converter timer
-Voltage converter relay
-Starter relay

After sitting down and drawing this out I relized the 12 volt system must be shut down and seperated from the 24 volt system, not a easy feet or am I missing somethihg?

Thanks
Rob

You kind of scare me with this comment. My LC has 2 batteries, starts on 24 volts and everything else is 12 volts. There's a solenoid or relay that combines the two batterires for the starter and the starter only. I believe do the same parts are available in the States. The original Toyota part costs an arm and a leg.

I've been told my alternator takes care of giving a charge to whichever of the two batteries needs it, but I haven't verified this yet.

There's an electrical diagram for the 80 in Ellery's and it's for the Australian version, therefore probably the same as the Japanese version.


Kalawang

 

[Radd Cruisers]

Wussypup sent me the wiring diagram, what it tells me is there are more components in the 81 to make this work.

Yes to Icky and the 12 volt starter motor, I did this conversion on a 1HZ about 1 ago, it works great.

Nick, thanks for the help and I appreciate your effort but I think its just a decision I have to make whether to wire this beast up for 24 volt start or not at this point.

I am leaning towards the simple and sweet 12 volt method....

Thanks for allt he input and help.


Rob

 

[Behemoth60]

I purchased a 200A series parallel switch on e-bay for about $50.
Something a lot like item 7956113694 on ebay right now.

Peter Straub

 

[Radd Cruisers]

Do you think its worth the trouble?

I purchased a 200A series parallel switch on e-bay for about $50.
Something a lot like item 7956113694 on ebay right now.

Peter Straub

 

[Mainer7]

Rob,

If you're going with the 24volt starter, I can say from my experience the marine series parallel solenoid switch works great. It lets the starter have what it needs during cranking, and it also equalizes the 2 optimas. I've been running it for almost 20 months now and let is take the last winter "off." The other day it started up no problems...Anyway good luck.

Jim