Hello,
If you are trying to install a modern 12 volt radio/CD/cassette Head Units into a 6 volt negative ground vehicle, below are some wiring diagrams and special wiring instructions.
Modern aftermarket automobile stereo in-dash radios CD/cassette Head Units require special wiring.
The RED wire that normally goes to the vehicle ignition Accessory switch is internally connected to a voltage sensing circuit. When the ignition is switched on, 12 volts is applied to the RED wire, the voltage sensing circuit senses voltage and turns on the CD player, pre-amplifier and power amplifier circuits (standby mode). They do this so you don't have to turn on the Head Units power switch to play a CD.
With the engine off ignition switched on or in the accessory position and the Head Units power switch switched off (standby mode), you can insert a CD into the Head Unit and it will power up full on and start playing without turning on the Head Units power switch.
If you do not remove 12 volts from the RED voltage sensing wire the Head Unit remains on or in a standby mode which will result in the battery to drain.
The Head Units on and off switch does not fully shut the Head unit off; you have to remove 12 volts from the RED voltage sensing wire (to shut off standby mode) to prevent the battery from draining.
The YELLOW wire has two functions; it supplies minimal amperage draw constant 12 volts to the microprocessors to maintain clock time and radio station presets (which is not enough to drain battery). The other function is to supply 12 volts to the Head Unit for main system power during standby and full On, when 12 volts is applied to the RED voltage sensing wire.
Obviously when the engine is running, the battery is charging, there are no dead battery issues.
There are two ways to disconnect the RED wire.
Automatic disconnect Diagram 1 Check picture
Manual disconnect Diagram 2 Check picture
JVC manual states this about Red wire. Check picture
Note:If you go the Toggle switch route you can save yourself a few bucks if you don't mind flipping another switch after switching the ignition switch off.
Go to this
POST .
To add a 12 volt battery to your 6 volt vehicle without converting the whole
vehicles electrical system to 12 volts.
Thanks,
xfiles
