How to start a 24v HDJ81 with 12v video (1 Viewer)

[Squash]

Starting a 24 volt HDJ81 with 12 volts.
Soldered in from relay.
Look for the black and red wire at white plug.
I soldered above the plug and below the relay by removing the relay. Lift tabs in plugs to remove.
Using a momentary switch to feed 12 volt power

 

[Cavalier2000]

I must have missed something. But why?

 

[Squash]

Why you ask.
Well if you've every been stranded it's good to know you can turn the 24v starter with one 12 volt battery.
I lost the24 volt key start during this Canadian winter yet still needed to drive while I sorted out the problem. Mind you when it hits -20 below it helps to have a coolant heater when using 12 volts.
I travel off main roads always so this mod gives me some peace of mind because there is no cell coverage and you may not see anyone for days.
The 24 volt starter is Superior because it really cranks the engine over, so I would never part with 24v.
The 12v momentary switch also allows key off engine bumping in case you need to work on the engine.
That's why.

 

[MUDZLLA]

Hmmm

 

[Squash]

YouTube link working!
Fixed on first post as well.

 

[cruiser182]

That's handy to know, thanks

 

[jellis]

Super rad!!!! Thanks so much for the video!!! I assume if the key was on it would have fired up. Impressive that this worked even during the Canadian winter!!!!

A lockout switch would be an appropriate safety element, or just leave the fuse out until you actually need to use it.

I had a battery terminal melt way out in Canyonlands earlier this spring, this would have been a nice hack to have in the back pocket. I ended up driving straight home on the very last startup I could get out of the nubbin' of a terminal.

 

[Squash]

Works to maybe -20C.
Nothing works like 24 volts at -35C

 

[jellis]

Wow, that's pretty amazing it works down that low. My apprehension about switching to 12V start has been that I routinely see -15C/5F in winter at home, but also go to Wyoming where my wife's family lives and there -35C/-30F is the kind of weather that usually hits while we're visiting (of course). I have seen a few Canadian folks on here who have switched to 12V start, but they also live in BC. So thanks a lot not only for the data point on this, but also for providing a clever workaround for when elements of the 24V start system fail.