MH radio with engine off
The dashboard radio on our Ford E350 works great with the engine off and even has speakers over the dinette. Unfortunately putting the ignition switch in AUX causes the headlights to go on! I have no idea how to change that, but I figured I could convince that radio to go on without using the ignition.
The radio we have is an aftermarket Audiovox. Easy to pull out of the dash - just a gentle pry to pull off a plastic frame, then pull the radio out with two fingers. Lots of wires: eight speaker wires a ground wire (black) and two power wires (yellow and red). The wiring is clearly marked on the radio itself and in its manual. The yellow has 12 volts all the time, the red when the ignition is on or in AUX. I see in the Ford manual, there is a third power fuse live when the ignition is in cranking position.
The yellow wire has a 10 amp fuse inline and a choke in a little black box. The radio pulls 30 mA from the yellow wire all the time for its clock, plus 300 mA when the red wire is energized and the display lights up, over 1 amp when the radio is turned on. The red wire supplies 15 mA with the radio off and 65 when it is on.
I could have just connected the red to the yellow to make the radio available all the time - at the cost of drawing 315 mA all the time. I chose to use a switch to toggle the red wire between the existing AUX supply and direct to the always on yellow. I happened to find a switch that fits snugly into the CD storage shelf which we have never used.
It doesn't look professional but is functional. Very handy for us.
The radio we have is an aftermarket Audiovox. Easy to pull out of the dash - just a gentle pry to pull off a plastic frame, then pull the radio out with two fingers. Lots of wires: eight speaker wires a ground wire (black) and two power wires (yellow and red). The wiring is clearly marked on the radio itself and in its manual. The yellow has 12 volts all the time, the red when the ignition is on or in AUX. I see in the Ford manual, there is a third power fuse live when the ignition is in cranking position.
The yellow wire has a 10 amp fuse inline and a choke in a little black box. The radio pulls 30 mA from the yellow wire all the time for its clock, plus 300 mA when the red wire is energized and the display lights up, over 1 amp when the radio is turned on. The red wire supplies 15 mA with the radio off and 65 when it is on.
I could have just connected the red to the yellow to make the radio available all the time - at the cost of drawing 315 mA all the time. I chose to use a switch to toggle the red wire between the existing AUX supply and direct to the always on yellow. I happened to find a switch that fits snugly into the CD storage shelf which we have never used.
It doesn't look professional but is functional. Very handy for us.
