24volt to 12 volt conversion - Nissan

[Jaymz]

Just to bounce some ideas off you guys regarding voltage conversion.

It is in a Nissan Safari, but the principle remains the same.

The current situation:

The Safari runs a 24volt system (comprised of two 12volt batteries in series:


It came factory with a 12volt tape deck and CD player (Sony and Nissan branding).

The CD player was stuffed and the tape deck chewed tapes and had the Japanese radio frequencies, so the decision was made to rip it out and put in another head deck.

A cheap Panasonic CQ-RW122W was purchased along with the appropriate wiring harness adapters.

Plugged it all in, with no go, the thing wouldn't power on. Found the issue, no earth from the factory harness (factory earthed through the unit itself). Simple fix, run a earth wire and it started up fine.

However, when a CD was put in it went into a power cycle, where it would turn on and off again over and over again.
Tested the unit in my VS, it worked fine.

Found out that the Nissan has a factory 24volt to 12volt converter in it (Clarion EP-693H).

Quick google search revealed that these issues (head unit powering on and off again) was a symptom of the converter not being able to supply enough Amps to it. (see here: GQ Replacement Stereo [Archive] - NissanPatrol.com.au Forum)

I have had a look around and found a few converters which might do the job, but need to bounce the idea off you guys first.

The head unit is only suppose to draw 2.1Amps (http://www.5starcaralarms.co.nz/manu...0322%20420.pdf)
I found a converter at JayCar which puts out 3Amps (24-12V 3A Converter Module M038 - Jaycar Electronics)

However reading on some of the forums, other guys suggest a Redarc converter (Linear Voltage Reducer | Redarc Electronics)

The question is, can i get away with the JayCar one, or should i go with the Redarc one? How much power will the Panasonic draw?

cheers in advanced

[AmmoJammo]

assuming you're running speakers off the headunit, I'd want a voltage regulator that did at least 10amps.

[Jaymz]

Good point, it has the factory 4 speakers so that will add extra load.

I found this one: 24 -12V DC-DC Converter 10A - Jaycar Electronics
And upon speaking with JayCar they said that he had a guy come in and buy these for their guy to run radios in their diggers. Sold it for me, will pick up one tomorrow and see how it goes.

[AmmoJammo]

you need a 12volt constant, and 12volt accessories though.

so the headunit turns on when the accessories are turned on, and also so it keeps the radio presets.

[Jaymz]

yeah, the factory converter (Clarion EP-693H) had a nice little wiring diagram on it which will make things easier.

The nissan is about 1 hour away so can't write down what was on it, but with the radio running though it at the moment it is keeping the pre-sets.

The idea is to take the 24volt input on the current converter and put it into the new converter and run new wires from the new converter to the new head unit (if that makes sense. I drew a pic that helps explain what i mean:



I will either run it as the pic, or simply replace the converter as one whole thing, but i need to confirm that the new one will do all that the old one does. If the new one doesnt have all the correct pins, then i will only use it for the radio.

Jeez i hope i am making sense!

[axemurderer101]

you might need a 24v relay aswell so you can have 12v accessories and 12v constant

[Jaymz]

the converter that i brought had a relay in it already.

Basically just wired it up as per my diagram above and it worked mint! had to run seperate wires to the head unit from the new converter though, the car loom didnt have an ACC wire from the original converter to the head unit. wired it up and it works a treat!