1HDT 24v to 12v conversion step by step (1 Viewer)

[FlyAddiction]

12V STARTER SWAP

The current 24v starting worked great but the need to have an isolated house battery and the safety factor of being able to self jump-start indicated the needed swap. I kept the driver side battery as the Main (start) and the passenger side as the House (aux).
1-
Disconnect and remove all wires attached to the the 24v starter solenoid located behind the passenger side battery.
Remove the starter solenoid.

2-
you will be left with 1 grey plug with 2 green wires and 1 white wire with a ring terminal. Cut those 3 wires and connect them all together using a heat shrink/crimp connector.

3-
Disconnect the starter+ and the small negative connector from the starter. Remove the original starter and replace with 12v version. Connect the negative connector just like the original and run a new cable from starter+ to Main+. (I used 2/0 welding cable for almost all my connections as it was free.)

4-
Ground both batteries to existing body and engine grounds

5-
Connect Main+ to Battery Isolator(I used Battery Doctor 150amp), Battery Isolator to 150amp fuse, Fuse to House+

6-
you will be left with this wire originally connected to passenger side+. Use a heat shrink butt connector and extend it to the Main+ post

7-
make a new wire from alternator to Main+

I think that's it...
I used a Blue Sea 5511e between the Main+ / starter and the House+ / Fuse box. This allows me to shut everything off with one switch and combine both batteries for self jump-start or winching.
I used dual wall heat shrink on the Full length of all wire and wiring loom almost everywhere.
Tin plated cooper lugs were used throughout.
All the small wires connected to the driver side battery+ will remain connected to the Main+
Batteries: Eliminator Ultra XD 34/78 AGM battery for the Main and a Nautilus Ultra XD Group 27 AGM Deep Cycle for the House.

 

[FlyAddiction]

Isolator and Fuse bracket.

Main

House

I am open to constructive criticism. Please chime in if you see possible improvement.
The whole job took me approximately 24h and cost 1700$ Canadian including batteries and starter.
Big thanks to SHREDWagon for his valuable insight and or allowing me to take a peak at his rig!

 

[FlyAddiction]

Blue Sea Battery switch bracket mounted beside the air box intake.

 

[absalom]

How's the start times now? I wouldn't trade my 24v system for the world ... I love just "bumping" the starter to have an instantly running truck

 

[FlyAddiction]

Same as before, down to -5 without plugging my coolant heater. Wouldn't go any colder without plugging it

 

[maat]

How's the start times now? I wouldn't trade my 24v system for the world ... I love just "bumping" the starter to have an instantly running truck

thats more to do with the fact that its direct injection

 

[IanB]

That's a pretty slick setup, boost yourself at the flick of a switch, I like it!

 

[veiloctane]

hey quick question on why the "house battery" is not the "main" battery?

to me it would make more sense to have the setup flipped around because all the main fuses of the truck are on that side and the starter is on that side too. the other side already has factory aux power fuses.

can you please explain to me how the main battery and house battery was chosen?

 

[Douglas S]

I set mine up so the LHS battery is responsible for starting the truck only.

The RHS battery handles everything else.

 

[Douglas S]

How's the start times now? I wouldn't trade my 24v system for the world ... I love just "bumping" the starter to have an instantly running truck

You say that until you want to park the truck and use accessories, or an issue with one battery kills both of them leaving you unable to start the truck.

I'm very happy I converted, no regrets whatsoever and I winter drive my truck in a cold climate.

 

[veiloctane]

I set mine up so the LHS battery is responsible for starting the truck only.

The RHS battery handles everything else.

That's how I have mine setup LHS battery starts truck RHS everything else. Only difference im using is a Ctek d250s + smarpass I'm planning to hook up a solar panel in the near future.

 

[Douglas S]

That's how I have mine setup LHS battery starts truck RHS everything else. Only difference im using is a Ctek d250s + smarpass I'm planning to hook up a solar panel in the near future.

I have a Blue Sea ACR in the bay to handle isolation. Planning on using a D250S to handle charging and solar for my trailer. It looks like a nice unit.

 

[FlyAddiction]

I decided on the rhs battery as the main to ease the connection of the wires pictured bellow. You end up with a shorter run from the alternator but a longer one to the starter. More or less the same amount of wire is required either way. The use of the bluesea swich almost double the amount of wires needed because batteries + , starter+ and aux fuse box + all need to be connected to it.

 

[b702012]

Great Setup and many thanks for sharing.

Did you upgrade your alternator? And how is the new setup working out for you

Looking to change my system too to 12V in the next couple of weeks and I was wondering if you can share part number of the 12V Starter?


Thanks

 

[dirtyboots]

@FlyAddiction excellent write up and thank you for sharing..also interested in a couple of explanations if you don't mind-

As mentioned before a part number for the 12v starter would be great

How did you decide on which battery goes where, what manufacturer and model?

 

[FlyAddiction]

I can not recall the exact part number but is it the one that came on your ebay.au recearch if you look for a 12v 1hdt/1hz starter.

See 2 post up about the battery location

As for battery choice, the "motomaster eliminator ultra xd" for the main and the deepcycle "motomaster nautilus ultra xd" for the house. They are both "affordable" agm batteries that are made by optima.(apparently exactly the same).

Been on the road for now over 2 months and it ran flawlessly. No problem keeping up to the fridge for 3 days straight without charging in +30c.

 

[b702012]

Just completed my conversion from 24v to 12v, greatly appreciated the feedback and info from Flyaddiction and Douglus S. I went with IBS system

IBS Dual Battery

• b702012
• Feb 27, 2017

 

[OkiGoose]

I may be showing my ignorance (or just be new) but is there any reason you can't convert to 12v starter and just wire it without the switch etc? I don't plan to run a fridge/have the truck pulling power for days/ etc.

I guess what I'm really asking is this. Can I convert to 12V starter and wire the truck so that I can run my door speaker amp and some lights off either battery without having to install a switch? I only use these items while driving (charging) and for a brief minute in accessory when parked.

 

[Douglas S]

I may be showing my ignorance (or just be new) but is there any reason you can't convert to 12v starter and just wire it without the switch etc? I don't plan to run a fridge/have the truck pulling power for days/ etc.

I guess what I'm really asking is this. Can I convert to 12V starter and wire the truck so that I can run my door speaker amp and some lights off either battery without having to install a switch? I only use these items while driving (charging) and for a brief minute in accessory when parked.

You could certainly do that. Just remove the series/parallel switching system and connect the batteries in parallel.

 

[TuffMudder]

I'm about to do the 12v conversion and came acroos this thread. Great write up, but i did have a question. In your OP topic 2 you mentioned connecting 3 wires. Is this just with a crimp cap and then leave this sitting to the side in case you want to undo your conversion ?

12V STARTER SWAP
2-
you will be left with 1 grey plug with 2 green wires and 1 white wire with a ring terminal. Cut those 3 wires and connect them all together using a heat shrink/crimp connector.