JDM radio replacement 24v vs 12v

[RHD Cruiser]

I have a 93 Hzj73 that needs a radio. If have read multiple opinions on the 24v system with accessories. Does anyone know confidently if I can use a 12v stereo, or do I need to convert it using a step down converter? I would like to find a similar era Toyo head unit to install and most have plugs that line up, but worried about frying the system if it’s not converted to 12v. I want to keep the stock look since the few that are out there usually have been bogered up with crazy Japanese accessories. I have heard all accessories run of a 12v already and the 24v is only used for starting the truck, and I have heard the opposite. Not sure which to roll the dice with! Thanks in advance for any experience offered!

 

[Sundowner]

Most everything in my '90 is 24-volt; I actually installed a 24/12 converter in order to handle adding 12-volt stuff as needed...so, there's your answer, on all fronts. That being said:

• You can use a 12-volt stereo with no serious work at all, you just have to pull 12 volts from one of your batteries...but this is a very bad idea, because you'll end up prematurely killing the battery from which you pull the 12-volt drop. Previous owner of my rig did that; I ripped all of that system out, and then still had to replace the batteries.
• You may have a voltage converter behind your glove compartment; pull the insert out and see what you find. I'm not sure of what amperage they handle (I was actually going to check and see if I have one, later today) but it might be enough to power a head unit. I'm honestly not sure if that's what they were originally for; I should probably check the chassis diagram and find out.
• 24-volt head units aren't impossible to find; you can come across working OEM stuff here and there, and there are some acceptable aftermarket units as well. If you install or find a 24/12 converter, all bets are off; run whatever you like.
• Accessories on a JDM 73-series with a 24-volt bus are 24-volts, for sure; every little bulb and switch light are all set up to use that voltage. Pull out your meter and test, if you have any questions about what voltage something is using...but it's gonna be 24-29 volts, basically everywhere.

Hope that helps...and - again - when in doubt: pull out the meter.

 

[RHD Cruiser]

Most everything in my '90 is 24-volt; I actually installed a 24/12 converter in order to handle adding 12-volt stuff as needed...so, there's your answer, on all fronts. That being said:

• You can use a 12-volt stereo with no serious work at all, you just have to pull 12 volts from one of your batteries...but this is a very bad idea, because you'll end up prematurely killing the battery from which you pull the 12-volt drop. Previous owner of my rig did that; I ripped all of that system out, and then still had to replace the batteries.
• You may have a voltage converter behind your glove compartment; pull the insert out and see what you find. I'm not sure of what amperage they handle (I was actually going to check and see if I have one, later today) but it might be enough to power a head unit. I'm honestly not sure if that's what they were originally for; I should probably check the chassis diagram and find out.
• 24-volt head units aren't impossible to find; you can come across working OEM stuff here and there, and there are some acceptable aftermarket units as well. If you install or find a 24/12 converter, all bets are off; run whatever you like.
• Accessories on a JDM 73-series with a 24-volt bus are 24-volts, for sure; every little bulb and switch light are all set up to use that voltage. Pull out your meter and test, if you have any questions about what voltage something is using...but it's gonna be 24-29 volts, basically everywhere.

Hope that helps...and - again - when in doubt: pull out the meter.

Thank you Sundowner! I really appreciate the time you took to type all this up! You got me thinking so I went out and dug a little deeper. I actually found a factory converter behind the glove box. Toyo part #86206-60031 Converter Sub-Assy, Voltage. I am assuming this is a factory step down, but not completely sure. I wouldn’t know what else it would be used for. I guess your last line sums it up, need to get a meter on it and see what I got!! Thanks again for the great info!

 

[Sundowner]

Thank you Sundowner! I really appreciate the time you took to type all this up! You got me thinking so I went out and dug a little deeper. I actually found a factory converter behind the glove box. Toyo part #86206-60031 Converter Sub-Assy, Voltage. I am assuming this is a factory step down, but not completely sure. I wouldn’t know what else it would be used for. I guess your last line sums it up, need to get a meter on it and see what I got!! Thanks again for the great info!

You're welcome. If you don't have a full chassis diagram, just do a bit of digging both here and elsewhere and you'll come up with one. I mean, if my pathetic Search-Fu can locate one, I'm sure you'll find a dozen.