Open Roads Forum

Print  |  Close

Topic: Radio draining my chassis battery when switch set to Coach

Posted By: Roadfrog on 07/13/09 07:16pm

Last month I did a mod that involved the installation of a SPDT switch that allows me to switch from chassis to coach to operate the radio. To the center pole I hooked up the radio. On the other ends of the switch, I wired a power wire from the coach and the other end I connected the chassis power. However, when I flip the switch to "coach", it draws power from the chassis battery (confirmed with an ohm meter on the starting battery). If I disconnect the coach wire though, the radio turns off, so I know it's running from the coach battery. So where is the power draw coming from? I'm completely stumped! Here is the mod in more detail: Radio switch

It was described by another member as follows:
"Pull your Radio out and find the wire to use. On my Ford, it's the yellow with the black tracer. Cut this wire and wire the radio side to the center of the switch terminal 2. Wire the harness side to either 1 or 3 it doesn't matter, and wire the one from the coach side of the solenoid to the terminal that's left".

So....any clues folks????


Cheers
Chris

1999 Winnebago Itasca Spirit 29N
1988 Campion Allante 195


Posted By: Harvard on 07/13/09 07:24pm

There could be 2 power wires, one for the radio and another for the lights in the radio.


Posted By: Kirk on 07/13/09 07:29pm

What happens if you lift the lead that comes from the chassis side of things?

As an electronic tech, I would have to see what you have done perhaps take some readings to see what is happening.are you telling us that if you leave the radio off, the chassis battery does not run down?


Good travelin! ........Kirk
Professional Volunteer
Fulltimer for 11 years,
URL: www.adventure.1tree.net



Posted By: pigman1 on 07/13/09 09:07pm

copeland343 wrote:

You have two power wires one for memory and the other to turn the radio on. You might have only moved the memory wire and not the power wire.
That's the reason, for sure. The memory lead will draw minimal power whereas the power lead is the big draw. Go behind the radio to tap the right wire.

John


Pigman & Piglady
2013 Tiffin Allegro Bus 43' QGP
2011 Chevy Silverado 1500
BlueOx Aventa LX Tow Bar
SMI Air Force One toad brake
Street Atlas USA Plus


Posted By: copeland343 on 07/13/09 07:52pm

You have two power wires one for memory and the other to turn the radio on. You might have only moved the memory wire and not the power wire.


Posted By: MNtundraRet on 07/13/09 07:57pm

The chassis circuit and house (coach) circuit were designed to be isolated. There are solenoids to connect them at proper times. Your DIY work on the radio may have connected the two circuits. The chassis battery may be running down not from the radio being on, but from detectors or other options now drawing from the chassis battery, especially if the house-batteries are on disconnect when stored. Because of thinner plates in the chassis starting battery, it will naturally discharge faster in preferrence to the deep-cycle house batteries. Because of the ground you may have created an always "on" chassis and house circuit (radio on or off).

Mark


Mark & Jan "Old age & treachery win over youth & enthusiasm"
2003 Fleetwood Jamboree 29



Posted By: Roadfrog on 07/15/09 08:54pm

It's all done....thank God. I spent way too much time on this one. LOL.

Everything now works as it should and it's a great mod. So to summarize for those interested in doing it:

All memory and power (yellow wire) come directly from the House/Coach batteries.

Red wire (ign/acc) from the radio goes to one side of the switch

" " " from the chassis side of the ign wire goes to the center pole

A separate wire from the third pole (or other end of the switch) goes to the coach battery +

As hoped, the radio works with the key in acc or run with the switch in one position. When switched to the other position, the radio works regardless of key in ign or not. Center position, no power at all axcept for the memory wire keeping the presets, clock, EQ settings, etc.

No more power drain from the chassis/starting battery.... ever.

Thanks for all your input and patience folks!


Posted By: Roadfrog on 07/15/09 08:11am

Okay, I think I have it solved, but now need to figure out how to get around it.

The issue comes from the yellow wire. It is not switched so it's draining the chassis battery when on. The switch was installed on the red wire which is only the ign power on wire. Problem is how to get around having the yellow wire switched to coach (and back to chassis again), without losing the station memory, radio settings, etc.

In a previous post I did way back, a few people here mentioned a double pole double throw switch. I used a SPDT switch. Would that somehow get me around this issue?

Quote:

Move both power wires on to the house battery, What is the switch for? Just connect it to the house battery and be done with it.


That will be my last option. There are several reasons why I went the switch route (as found on class A's and many class C's). For one, when I switch off my coach batteries, I won't lose my radio settings, station memory etc. Also I won't have to turn off my radio on and off everytime we get in and out of the RV while travelling.

* This post was edited 07/15/09 08:17am by Roadfrog *


Posted By: Roadfrog on 07/14/09 10:18am

Thanx for all the resposnses so far. I really need to get this done and put everything back together.

I have two power wires on my stereo - one is the yellow wire (12 volt pos), which I connected to the yellow/black tracer and switch. The other one is the lighter gauge red wire (12v pos ign) that goes to ignition. This one I connected to the chassis. Perhaps this red wire is drawing power?

Quote:

What happens if you lift the lead that comes from the chassis side of things?

As an electronic tech, I would have to see what you have done perhaps take some readings to see what is happening.are you telling us that if you leave the radio off, the chassis battery does not run down?


I'm not sure what you mean "lift the lead". However, yes...if the radio is off, there is no longer any power drain. I did the testing with the leads on the ohmmeter attached directly to the chassis/starting battery. Voltage steadily drops as the radio is on, but then goes back up steadily after turning it off.

Bob, did your stereo have two power wires?

* This post was edited 07/14/09 10:26am by Roadfrog *


Posted By: Hurricaner on 07/14/09 10:59am

Move both power wires on to the house battery, What is the switch for? Just connect it to the house battery and be done with it.

Sam


Sam & Kari
Hurricane, Utah


2004 34' Damon Challenger 315


Posted By: csp et2 on 07/14/09 05:08am

Chris... Don't know what's going on, but mine is fine.


Bob


Print  |  Close