Seattleguy Posted January 11, 2011 Share Posted January 11, 2011 Wondering how difficult it may be to switch the radio/CD player to run off the coach battery instead of the engine battery. I have a great sound system now, but would prefer to have it hooked to the coach battery, so as to not drain the engine battery when parked. The previous owner had done this in my Dolphin. Wondering if anyone else has and what may be involved? Thanks! Quote Link to comment Share on other sites More sharing options...
Lee & Joan Posted January 11, 2011 Share Posted January 11, 2011 You will need to run a 12 volt plus wire from your power panel in the coach (fused) to your dash. Then you find the 12 volt power from your engine circuit to the stereo. Cut into that wire and put a single pole double throw switch in. Put your two 12 volt source wires on the outer terminals of the switch and run the center terminal to the stereo. This way you can run off the engine circuit on the road and switch to cabin power when parked. Quote Link to comment Share on other sites More sharing options...
Maineah Posted January 11, 2011 Share Posted January 11, 2011 You could hook it to the isolator wire coming from the coach and once it's started both batteries would be joined together any way. As Lee&Joan said an inline fuse would be a real good ideal. Quote Link to comment Share on other sites More sharing options...
Seattleguy Posted January 11, 2011 Author Share Posted January 11, 2011 Thanks for the tips. Now that I think of it, there is a double throw switch that I didn't know what is for...maybe it's just that. I will have to tinker with it. Quote Link to comment Share on other sites More sharing options...
Gulfstream Greg Posted February 4, 2011 Share Posted February 4, 2011 Modern radio/cd systems usually have two power leads. One is main power, the other is supply for the memory. I have both wires connected together, they connect to the coach side of my isolator. That way the radio/cd always uses coach power, No toggles. I don't want auxiliary equipment to use the starting battery. Quote Link to comment Share on other sites More sharing options...
Tony D. Posted February 8, 2011 Share Posted February 8, 2011 You will need to run a 12 volt plus wire from your power panel in the coach (fused) to your dash. Then you find the 12 volt power from your engine circuit to the stereo. Cut into that wire and put a single pole double throw switch in. Put your two 12 volt source wires on the outer terminals of the switch and run the center terminal to the stereo. This way you can run off the engine circuit on the road and switch to cabin power when parked. If you power your radio via a toggle switch what happens to your clock every time you flip the toggle switch? If you power your radio from the engine battery then how do you use your remote without leaving the truck ignition switch turned on? I just installed a new battery and I was also considering hooking up to my coach battery but was concerne about the times when the battery gets low. Quote Link to comment Share on other sites More sharing options...
Derek up North Posted February 8, 2011 Share Posted February 8, 2011 All modern radios I'm familiar with generally have 2 wires supplying power to the radio 'head'. 1 is wired in to be 'hot' all the time to power the clock and keep your preselected stations in memory. The other is 'keyed hot' to make the music. This is the one you would install with a toggle switch to select the battery you want to power it. Quote Link to comment Share on other sites More sharing options...
waiter Posted February 8, 2011 Share Posted February 8, 2011 The photo is from my 88 Dolphin. This is the standard Toyota Radio connector that is in the dash. I believe National installed a cheep AM/FM radio in the truck. They cut the power lead from the original harness and used that for their power. (this is the gray wire that has a piece of black tape on it) When I installed a 94 Camry radio, I had to repair the wire they cut, and connect the speakers to the Toyota harness. Anyway, the gray wire is Accessory Power (12 volts when key on) and the Blue (with yellow strip) is 12 volt battery (stays hot all the time) I also included a link to Install Dr. they give a color code for the two different model years (Toyota) NOTE - the Install Dr color coding is not complete, there is an additional wire that is used for the panel instrument lights that utilizes the smaller connector on the radio. However, this connector is different on the truck than on the Camry. I'll print more on this later when I receive the harness I bought from E-Bay and get the instrument lights hooked up on the radio Quote Link to comment Share on other sites More sharing options...
waiter Posted February 8, 2011 Share Posted February 8, 2011 Install a switch so the Truck radio can run off either the Coach or the Truck battery. Easy to do. You need a SPDT (Single Pole Double Throw) toggle switch. 1) Install it where it can be reached conveniently, on the dash or under one of the cabinets. 2) On one side of the switch, run a wire to the DC Converter, and connect it to one of the fuse terminals, maybe put a 5 amp fuse if you have an unused terminal. PHOTOS - Old and new style converter. Note that both have unused terminals. 3) On the radio connector, Cut the power lead to the radio. 4) On the wire that you just cut, Splice a wire that goes to the radio, and connect the other end of this wire to the center terminal of the SPDT switch. 5) On the wire just cut, Splice the other side of the wire (the side that has power when the key is on) and connect this to the other outside terminal on the SPDT switch. At this point, The SPDT switch should have the three terminals with wires connected. The two outside terminals will be where the power comes from, and the center terminal goes to the radio. The switch should now work. One position will be the Coach Battery, and the other position will be the Truck, when the key is on NOTE - To assist with inadvertently leaving the radio on and in the Coach position, I would consider putting a small LED light fixture near the switch., Wire the LED so that anytime the switch is in the COACH position, the LED lights as a reminder. I was thinking of doing this switch mod, but I purchased and installed an AM/ FM/ DVD/ TV player that mounts under the cabinets. Quote Link to comment Share on other sites More sharing options...
Tony D. Posted February 8, 2011 Share Posted February 8, 2011 All modern radios I'm familiar with generally have 2 wires supplying power to the radio 'head'. 1 is wired in to be 'hot' all the time to power the clock and keep your preselected stations in memory. The other is 'keyed hot' to make the music. This is the one you would install with a toggle switch to select the battery you want to power it. Derek, I considered doing this but was unsure about being connected to two batteries at the same time. I was unsure about the two circuits (the clock and the music) staying separate inside the radio when connected to the coach. Thanks for all the suggestions. Tony in Lousiana Quote Link to comment Share on other sites More sharing options...
Derek up North Posted February 8, 2011 Share Posted February 8, 2011 Just use a 2-position switch the is 'On-On' and not 'On-Off'. Quote Link to comment Share on other sites More sharing options...
Gulfstream Greg Posted February 9, 2011 Share Posted February 9, 2011 Why do you need to toggle running the radio from the truck or coach? What is the benefit of running it from the truck battery besides allowing the key to turn it on or off? Does the radio not have its own on and off switch?Just curious. Connect both leads from the radio to the coach side of the isolator via a fuse and be done. Here is the fuse holder from radio shack. Water tight, uses the same fuses that your truck uses. Quote Link to comment Share on other sites More sharing options...
waiter Posted February 9, 2011 Share Posted February 9, 2011 Greg brings up a good point, You could simply re-wire the radio so that it uses the coach battery all the time. The only issue here, you need to remember to turn it off or you'll run your coach battery down. You can pick up the coach power off of the isolator, it should be on the drivers side firewall. Quote Link to comment Share on other sites More sharing options...
ynkedad Posted February 26, 2011 Share Posted February 26, 2011 A few days ago I was looking for a way to run my radio off the coach battery. So, before running a power wire directly to the coach battery itself, I decided to check this forum for a more simplistic way to accomplish my goal. And voila here's a thread with the info I needed. I've since hooked the radio to the isolator and ran the on/off memory wire to the radios power wire (in the cab.) Yeah, I have to remember to turn the radio off when not being used but, at least I don't have to worry about running the trucks battery down . Thanks for this thread, it sure made things WAY easier !!! Quote Link to comment Share on other sites More sharing options...
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