24v --> 12v Converter Questions (1 Viewer)

[unfortunately]

To preface, I'm very new to - and unfamiliar with - 24v systems and a bit of a dunce when it comes to electrical.

I just brought home an HJ61, and one of the first things to go was the old, beat up Walmart-special cd player. I installed the shiny new Pioneer bluetooth player and everything seemingly works great. However, I realized after coming back out to the truck to work on some other things, every time I start it up the new head unit takes me to the initial setup screen. After some troubleshooting I figured out the problem. The 24v ---> 12v converter that was installed by a previous owner (ICT Industrial Power Series 10, a 10amp model) only receives power when the ignition is switched to ON.

That leads me to some questions:

1) If I were to give the converter constant 24v power, would I be able to install some sort of relay/switch so that most accessories that need 12v only get it when the ignition is switched to ACC or ON? If so, is there an example of how this might be done? I may not the brightest when it comes to electrical, but show me how it's done and I can figure it out.

2) If I were to give the converter constant 24v power, would I be having battery drain issues? Even if the only thing connected to constant power is the head unit? i.e. Does the converter itself draw power?

3) Is the above mentioned converter ok? It seems like this one's been kicking around back there for quite some time powering the previous CD player as well as a triple cigarette lighter dock, that currently charges a couple of phones at a time, at most.

4) Should I ditch the converter and run a third battery, with something like this? Is there a cheaper, but still solid 24v ---> 12v charger out there?

Cheers!

 

[drenmaster]

i used my cigarette lighter wire for the acc into the converter since thats a "live wire" then i ran a new wire back to the cigarette lighter from the converter to run 12v accessories from it.

 

[Hilux safari]

I use a small 24/12V inverter that is installed in my glove box. You can get the 24v feed from the cigarette lighter, or in my BJ40 there is plug in my glove box, that I plugged into. The inverter powers my stereo and any other 12v accessory.

 

[BiffS]

IF you dig into the factory wiring behind the glove box or above it, there is usually a small factory 24-12V converter that can supply constant power to your stereo "keep alive" wire. That way, you don't have to reset the stereo each time.

On my last truck i did the following:

2x 15AMP converters
1X 60 AMP converter.
1X external battery in front of the rear axle under the truck.

with that set up, I sent a 6 GA wire from the 24V positive terminal to the 60A converter. It had a control switch that i connected to the 24V ignition. That allowed me to power / charge the third battery when the truck was running. I had my stereo, lights and compressors powered off the third battery which made it easy to run the stereo all night. If the third battery dies, the 24V system would still have full power. Start and run the truck and it charged the third battery after a bit of driving.

I've done a 24-12 conversion, so I have changed it now to use the third battery with a battery isolator.

(selling those converters now BTW

 

[unfortunately]

IF you dig into the factory wiring behind the glove box or above it, there is usually a small factory 24-12V converter that can supply constant power to your stereo "keep alive" wire. That way, you don't have to reset the stereo each time.

The "keep alive" wire is also the "all power" wire. The switched power is just a wake up signal, essentially. Is the factory converter enough to power the stereo? Will battery drain not be an issue with the factory converter?

 

[BiffS]

The "keep alive" wire is also the "all power" wire. The switched power is just a wake up signal, essentially. Is the factory converter enough to power the stereo? Will battery drain not be an issue with the factory converter?

The factory converter was something like 1 amp or so which may drain the battery in a few months or so.... The keep alive or memory wire / big converter for deck power system worked well for me for years. My truck came with a factory 12 v stereo wired this way, so I think it's safe to say that it is how Toyota intended it.

 

[unfortunately]

Well, today I wired up the head unit to the constant 12v from the factory converter. Works great, until a good song comes on and I turn up the volume. That results in the head unit skipping, and eventually powering off. My assumption is that the factory converter simply can't handle the load. It was a nice try though, and will work in the meantime if I keep the volume down.

My thoughts for next steps are:

1. I could buy a second aftermarket converter for constant power, keeping the one that was added by the PO for the switched power stuff.
   1. This seems like it would double the standby current drain, less than ideal. Also results in 3 converters in the vehicle
2. I could wire constant 24v to the aftermarket converter and use relays to switch power for "ACC" and "ON" post-converter.
   1. I don't see any real problems with this solution.
3. I could wire the accessories that require switched power into the switched power from factory converter, as they don't pull much juice, and then run constant 24v power to the aftermarket converter for just the stereo.
   1. This is probably the cheapest solution.
4. I could add a third battery, and charge it with a converter/trickle charger and run 12v accessories off the battery.
   1. Maybe the safest option, but also probably the most expensive. Not seriously considering it.
5. I could get something like this Cooper Bussmann Battery Equalizer and replace the current aftermarket converter entirely, using relays for "ACC" and "ON" power.
   1. It's a little overkill but they claim "Low standby current drain - typically 5mA or less". That's music to my ears. With the additional benefit of keeping the batteries balanced, it seems like a good idea. I'm leaning towards this solution.

Am I terribly misguided?

 

[60Works]

Search for Solar Converter Equalizer by a Mudder handled Stone. He pioneered the 24 to 12 V solution to radios and trailer lights. His solution has become the go to standard for many of us.

The SC Equalizer, like your proposed Bussman, allows you to tap the low battery for 12V without ruining the batteries from unequal charging. It also allows you to share the chassis ground, which you can't do when using a 24 to 12 converter. You have to run a dedicated 12 V ground wire to every component hooked to the converter.

 

[BiffS]

No do. I shared chassis ground all the time with no issues. But Stones solution is still s good one. It was nearly 10 years ago, so o have no idea if it's still around.

But 120% you can share the ground with converters. I did it for 8 years.

 

[Greg_B]

I'm scratching at the memory banks as I have not installed a car stereo in a while, but isn't there a mem-preset small yellow wire and main power red wire? IIRC you can then connect the yellow constant memory wire to the factory converter, then wire the red main power to the keyed aftermarket converter. Or did I miss that this is the way you did it and it's still cutting out.

hth's
gb

 

[unfortunately]

I'm scratching at the memory banks as I have not installed a car stereo in a while, but isn't there a mem-preset small yellow wire and main power red wire? IIRC you can then connect the yellow constant memory wire to the factory converter, then wire the red main power to the keyed aftermarket converter. Or did I miss that this is the way you did it and it's still cutting out.

hth's
gb

Mine is the reverse, and I believe this is now the standard, or at least very common:

The Yellow memory wire is several gauges thicker than the red "power" wire. The yellow wire serves as the constant power for the memory, as well as the main source of power for the unit. The thin red wire just tells the unit to power on when the ignition is turned, without actually providing any power for the head unit.

Essentially I've done what you said though, connecting the yellow wire to the factory converter, and the red wire to the switched/keyed aftermarket converter.

 

[Greg_B]

Mine is the reverse, and I believe this is now the standard, or at least very common:

The Yellow memory wire is several gauges thicker than the red "power" wire. The yellow wire serves as the constant power for the memory, as well as the main source of power for the unit. The thin red wire just tells the unit to power on when the ignition is turned, without actually providing any power for the head unit.

Essentially I've done what you said though, connecting the yellow wire to the factory converter, and the red wire to the switched/keyed aftermarket converter.

Right, thanks for the correction/clarification.

I have solar converters in my BJ42 and BJ74, for years now. I have had the one in the BJ74 hooked up to load balance the batteries, but found that the POT setting fluctuates a bit and needs adjustment. It might simply be due to vibrations and a dab of silicone could solve it, but I have not tried. I just unhooked and left in 24v-12v mode. The converters are on full time, so there is a slight constant draw. Try and find out the resting draw on your converter. I have the converter on quick disconnects and if I know I am going to not drive the vehicle for a while I put a 24V charger/maintainer on it or disconnect the converter out of the system.

Redac makes a load balancer as well.

On this thread a fellow posted up a link to used Vanner Vann-Guard 70-100M Equalizer 100Amp which looks interesting, if you are inclined to go the load balancing route.

If you park outside and plan on a solar setup...it's all moot.

hth's
gb

 

[unfortunately]

The solar route sounds very interesting, but a bit more complicated and expensive than I'd like, for now. I don't have a roof rack, and definitely don't want to drill into the roof. At over 7 feet tall (SOA, OME lift, 37's, high roof), I'm not really looking to add more height until I can bring the cruiser a bit closer to the ground. I'm looking at this Cooper Bussmann equalizer on eBay. I've made an offer below the asking price, and we'll see where we go from there.

 

[unfortunately]

Seller accepted my offer of $150 for the Cooper Bussmann converter. Here we go!

 

[Varty Yo]

Im curious where is your factory investor? Got a pic of it

 

[unfortunately]

Im curious where is your factory investor? Got a pic of it

It's not terribly complicated to get to, but I've got it all buttoned up now, and won't take it apart again until the battery equalizer comes in. I took off the door of the glovebox, and then pulled the glovebox itself out, and it was mounted under the dash, above the glovebox, if that makes sense.

 

[mongoose2231]

So as Jugg mentioned above, I have the same setup in my 24v truck. I have my constant for the radio and 12v gauges for the turbo coming out of the low 12V battery. I did not know about that member's setup as he mentioned but I done some research. So the converter powers my 12v accessories and the constant comes of the 12v prong on the low battery. I use a solar converter equalizer for balancing the charge. Works great. This is how I set everything up. I used a 24v relay to power the converter.

 

[Varty Yo]

Hmmm im thinking in my 42 i also have the prong in the glove box so that would be a 12v correct? Guess i could check lol

 

[unfortunately]

Hmmm im thinking in my 42 i also have the prong in the glove box so that would be a 12v correct? Guess i could check lol

Well, maybe. Definitely check with a multimeter before you plug something into it. I had no 12v in the glove box. I had to remove the glovebox completely to access the converter, but there is nothing going from the converter to the glovebox.

 

[unfortunately]

Here's what my factory converter looks like: ランクルP-HJ60V　63年式　アンプ86280　90A03☆N... - ヤフオク!