Radio Switch Drains Batteries?

[WVvan]

Thanks Mike.

Doesn't the memory and radio power come from separate circuits?

F2.3 yel/blk for radio power

F2.22 red/wht for memory power

This might be different between radios but in my case there is only one "power" circuit. It's the yellow wire on my adapter. The circuit is hot all the time so it supplies the running power and the memory power. The red wire is for the ACC circuit. This is only hot when the van is running (or you have the key turned to ACC). It doesn't power the radio as much as give it a signal.

I have one relay for the power circuit and one for the ACC circuit.

[Ultrasport12]

I put a switch and a relay in mine as well but what I did different is hook the constant 12 hot wire to the house batteries all the time. Since they are always charging and not doing much while driving I thought this might be easier than trying to switch that wire and have it loose memory or presets.

I fed the key/accessory wire into the relay on terminal 87a (constant closed) and the house battery to the 87 terminal and then used the 30 terminal as output to the radio. I know the other way would use a little less current but I don't really use that much power when camping anyway. I guess and we can go 3 to 4 days without starting the van before the house battery gets low. This way the radio always gets power from the battery and it works completely normal (door open delay and everything works normal) for day to day driving. When camping if I want to I turn on the switch (I have one in front and one near my bed) and I can have the radio working without the key and without any back feeding of the accessory terminal.

[BrianW]

Old thread, but I thought I'd add a tidbit that I just noticed when reading through the owner's manual from my 1998 Ford SMB. They say "The van starting battery can discharge if radio switch is set to 'extra battery.' About 3 amps per hour on extra battery and 1 amp per hour on van starting battery."


I added the bold. It is somewhat surprising that the switch mechanism (relay?) draws an extra 2 amps per hour. That's quite a lot.

[unordinare]

First post!

Purchased a 2002 SMB and having the same issue as some folks have described on this thread, but haven't figured out what I need to do yet. Hoping to do what Angel did but... How?

My switch is labeled "radio van battery" on and "radio extra battery" off. When toggled to "radio extra battery" the LED is on, and the radio drains the starter battery, real quick as noted in previous posts. I think neither toggle pulls power from my house battery.

Ideally I want the switch to function as-labeled, but will settle for pulling power from house battery, and using the switch as an accessory mode-key-bypass. Can someone provide some guidance? Thanks in advance!!

PS, I don't see/hear relays anywhere. Where might they be?

[marret]

So if the radio toggle is set to van battery and the van is off, does the starter battery drain?

With the radio toggle on extra battery, does the LED light go out if you pull the radio fuse in the house fuse box/panel?

If so it sounds like it is working as described above.

Don't know about relays.

Welcome.

[unordinare]

If the radio is on "van battery" and the van is off, the battery does not drain.

With the radio toggle on extra battery and the fused pulled, the LED turns off (no power).

I unplugged my starter battery (to charge). The radio now will not turn on, with toggle in either position. How can I get the radio to turn on fully independently of the starter battery? What was the intention of this toggle from SMB?

Thanks for your help!

[marret]

Your switch seems to work as designed.

The intention was to power the radio from either source although I do not know why there is still a starter battery draw as mentioned.

Don’t know if that has to do with the acc function.

There was mention of the amp being powered when the extra battery position is used regardless if the radio is on. The amp might be wired to the starter battery. That could be the source of the starter battery drain. Have you tried unplugging the amp to see if it makes a difference? My amp is under the gaucho.

If you wanted to only power the radio from the house batteries, you could rewire the radio to the house batteries directly, both acc and power. Still need to confirm the amp wiring,

[unordinare]

If the switch should change to house battery (as LED light shows it should), any thoughts to why the radio doesn't turn on when toggle is on "radio extra battery" when starter battery is unplugged? I guess it does have to do with some kind of acc key redundancy, that's my guess.

I'll check the amp, either way really appreciate the help and thoughts.

[Twoxentrix]

@unordinare, Other than testing to see if it functions as described, I've never used the vehicle stereo (powered off the house battery) while at a camp location (Partly because I wasn't sure how both Amp's would affect this).

This came from a Google search: "The average regular car stereo draws from about 2 to 10 amps. If you really turn up the volume, you're typically in the 8-12 range. However, if you look to upgrade your speakers, you'll likely be closer to 30 amps! If you upgrade, ensure your battery can handle the additional power."

Instead, we just use a couple wireless UE MegaBoom's which receive direction from my I-Phone. Being able to place them wherever I want around the campsite or campfire is a much better experience...plus we're take them down to the River/Lake, or with us on the bikes. They are great inside the van - overall just much more versatile.
These are backed up with wireless headphone; so we don't disturb others that may be close = just being respectful.

[marret]

You know I said acc which may be wrong, there is another wire for radios to keep their memory that may be called constant power. I really mean this, not the acc position on the column. This may be needed for the radio to power up, but that wouldn't explain the battery drain.

You are welcome.