E350 radio power

[Harvey51]

I would like to be able to use the radio without turning the ignition key on.

I see a wiring diagramfor the Ford radio is available in the first link of this just answer forum. There appear to be four power wires to the radio, hot all the time, hot in park, hot in acc or run, hot in start. I understand hot all the time for the clock and perhaps maintaining memory but why is power to the radio needed while the key is turned to start?

Anyway, my radio is an audiovox installed by the house maker, complete with speakers over the table. The Audiovox manual diagram shows a power wire direct to the battery! What is the idea of that? Might it get a better signal or less engine noise if that was done?

Any thoughts on this before I attempt to take the radio out would be appreciated.

[Harvey51]

Hmm, the radio draws 300 mA from the yellow wire when the red one is energized. Can't have that going all the time while camping or parking. Have to use a switch.

I would sure like to know if other Fords around 2004 have their headlights on when the ignition is on ACC.

[Harvey51]

Oh, oh, listening to the radio with ignition in ACC position isn't good. The headlights are on in ACC mode! I don't think they are full strength - probably driving lights. Any way to defeat that?

I'll fix the radio problem by using a jumper from the yellow power wire to the red wire input.

[Harvey51]

I appreciate your posts! I did think of connecting to the house power but was looking for a quick fix rather than a wire running job.

Turns out my problem doesn't exist! I thought I could only listen to the radio with the key half way to ON, which caused the heater fan to run and the seat belt alarm to bong. After looking at the Ford manual I found the accessory position is actually in the extreme anticlockwise position; in between off and on is the unfamiliar off but steering wheel not locked. I suppose that is useful for something?

Oops, the camera missed position 4: engine on, and 5: crank.

I was amazed how easy it was to get that radio out of the dash! I'm surprised it hadn't jumped out on its own. Just a gentle pry to pull the plastic surround off and then grab the radio with two fingers and slide it out.

All these wires! The manual diagram in my first post has the radio upside down so the eight speaker wires are shown on the right but they are on the left in the photo below.

The yellow wire has 12 volts all the time. This power wire comes through a choke in a little black box, presumably to reduce engine noise. The red wire is powered up when the ignition is on or in ACC and its voltage enables to radio to be turned on. It draws a full amp through the yellow wire, for the amplifiers I suppose.

[DrewE]

Generally, there are two power leads to car radios: switched with the ignition, and always live (for the preset memory and clock and whatnot). That's basically what the Audiovox instruction is showing. I think they show the wire going directly to the battery to emphasize that it's not switched at all; I certainly would want a fuse, at the least, on that line!

If you connect the switched line to unswitched power rather than switched power, the radio will operate regardless of the key position. As Kevin suggested, it makes some sense to just hook it up to the house electrical system. That's the way Coachmen wired things in my motorhome, in fact. Some motorhomes have a switch to select which electrical system powers the radio, but I'm not sure I really see too much utility in that option.

[ksg5000]

You ever consider hooking up your radio to your coach battery? Should take key position out of the issue.