Cab Radio Power Source Conversion

[BFRV2GO]

I'm attempting to modify the power source for the cab radio on my BF to be the household batteries. If anyone has accomplished this I'd love to hear from you. My concern regards the two purposes for power to the radio: 1) for the usual operation to play stations received, cassettes and CDs; 2) to support the radio's memory for storing station button definitions, current track on current CD being played and current time on the clock. The latter purpose needs power constantly while the former only needs power when the radio is likely to be turned on; i.e. either when the engine is on or when the ignition is turned to the accessory position. Ideally, I'd like to leave the secondary power source to continue to be the engine starting battery so that even when the household power switch is turned off, the radio clock time and the station button memory would be undisturbed. I could install a two way switch which would switch the power source back and forth between engine battery and household batteries only for the radio playing power source. But if I do that, is there any kind of electrical problem with leaving the radio memory (constantly on) power connected to the engine starting battery, i.e. would these to different sources of power connected at the same time cause an internal problem in the radio? Could I, instead of installing a switch, simply install a diode on each positive lead, one coming from the household batteries and the other from the engine starting battery, both connected to the radio playing positive power line? Any information on any of these options would be much appreciated. Thank you.
Chris Maple

[tomdclark]

Chris:

I did the sort of thing you are thinking about a few years ago for the radio on our 2005 RB and so far we've had no problems.
On our radio there are two power lines to the radio. The first for the amplifier, speakers, etc. is switched on and off by the cab ignition switch. The other for the memory, clock, etc. is always on.
I went to Radioshack and bought a two way switch (which happened to have center position off). I cut the main power line ( I unfortunately don't remember the color, yellow as I vaguely recall) at the radio and put this switch into the circuit in the manner you are thinking about.

As I said no problems after several years.

As I recall I also put an inline fuse into the line from the house batteries, but otherwise didn't do any diddling with diodes.

You will have to buy a special tool (typical Ford crap) to remove the radio. I think I got this at AutoZone.

Good luck.

Tom

[charlesbell]

When BF was building my coach in 2010 I requested the radio be hooked up as you are suggesting; allowing me to be parked at a campsite (on 110V power) for a long period of time (with the radio "on" most of the time) without worrying that the engine battery would be discharged. I don't know why it's not standard practice to connect the radio to the house battery. I had a Winnebago product many years ago that had a toggle switch to connect the radio to either battery. I thought that was a good idea.

[ewagman]

If you are going to be on 110 V AC most of the time, why not hardwire a battery tender to the engine battery, it will both power the radio from 110 V AC and keep the motor battery in 3 stage charged condition. I'd get the more powerful battery tender to keep up with the radios power demand. I would assume you will turn off the radio at night and when you are not at the coach, just in case you are drawing more than the battery tenders output with the radio cranked and the tape or cd motor spinning.

[bcope01]

Don't want to hijack this thread, but I use a battery tender (the smaller one) hooked up to my chassis battery all the time while my coach is in storage and plugged into 110VAC. Keeps the battery fully charged and conditioned with the 4-stage tender/charger. No more going out, turning the key, and getting nothing after extended storage periods. Good investment - cheaper that purchasing new batteries.

Bill