Radio Switch Drains Batteries?

[dowgars]

Paul: Thanks for helping. I don't understand the question. Am I sure about what? I'm not certain which of the batteres are being used. I assume when the switch is on "extra battery" the house battery is being used (4D) but then why does the key have to be in the ignition? And on ACC or ON. Thanks, RD

[dowgars]

I'll be calling Randy tomorrow unless a new idea pops up. Thanks for the help. I hate to spend the time and money to go to Fresno if I don't have to. I tried it again. If the key's not on I do not have radio over 10 min.

[dowgars]

Thanks guys. It was a fuse in the refrigerator fuse spot. I don't have a refrigerator like in other van's (mine is a refer/freezer combo). The master switch now operates the radio.

[Scalf77]

Glad to see the fuse fixed your problem. I suspect that your unit uses a relay to switch over from van battery to house battery. The Normally Connected side of the relay goes to the van battery, the normally open goes to the house battery. The 12 volts for the relay coil probably also comes from the same 12 volt fused circuit, so with out 12 volts you could never switch the relay, and thus you always stayed on the accessory controlled van battery circuit. I would think if people wondered if they had a relay or switch that would be one way to find out. Pull the fuse if it just stays on the van power then you probably have a relay, if you get no power at all, then it is probably just using a switch.

-greg

[Angel]

I can now upgrade my radio and use it in the evening because I GOT MY RADIO SWITCH FIXED. !!!!!!!!!! Thanks to Stereo John in Covina, CA. He an electrical engineer who, in addition to other things, has been restoring the electronics on boats, RVs, etc for years. He has his own business now. He was recommended by a friend who has been friends with him for years. I had a mess under my dash-wires changed colors, bare wires, and wires going no where. I needed someone with the know how and willing to take the time to do it right. PM me for his phone # if you want him to do any work for you.

Now, when I turn on the SMB radio switch, with the radio on or off, there is "0" draw from my starter battery instead of the previous 2 amp draw and It does not seem to draw as much from the house battery as it did from the starter battery the way SMB West had it wired. My battery will not be dead in the morning if I leave the switch on.

No extra switch on the dash and no memory loss in the radio. With the SMB switch off, the radio can be turned on or off at the radio when I am driving, like normal. When I turn off the Van, the radio memory switches to the house battery.

Angel

[PatO]

Well I have verified once again that leaving the van radio switch on drains the starter batteries. This time it was probably accidentally pushed but then I parked it for 9 days and there was nothing. I'm not sure my 3 year old batteries are going to come back from this. I'm trickling them at night and driving to work in the day plus running my AIC on charge for a few minutes after starting and before turning it off but it just doesn't sound that robust when cranking! Better here in town that coming back from a 4 day backpack! It takes me several hours to change them out so not looking forward to that. Maybe I should study this thread for possible solutions again!

[daveb]

What about a barrel key switch so you need the vehicle keys to activate it with. If the ignition key or alarm remote is back there as the radio switch, at least you can't drive off or forget to leave it past overnight.

I have my radar detector and my Garmin connected to the radio circuit. If I open the door and the units are still active I know the lousy radio switch is still on. At night I can't help but see the lights on.

[PatO]

Not that I'd mess with it but the IDEAL solution for me would be to have Ravelco plug in the middle of that circuit. hahaha - I remove that thing even when going into the store for 5 minutes~!

On Edit: One battery is toast and will not hold 11 volts so I am replacing both.

[WVvan]

I'm now at the radio battery switch stage of my conversion and this thread has been a big help. Didn't want to write anything till I got my version built, installed and tested which I have just now finished.

I've set mine up so there is a singe SPDT momentary switch that selects either house or van(starter) batteries as the power source. Once switched the radio runs totally off the source selected. The radio doesn't lose it's setting when switching between the two sources. I was worried about that but guess it just happens fast enough that the radio doesn't lose it memory.

To do the actual switching I'm using two 12 volt relays. These relays are rated for 16amp. They are dual coil latching type. Since they are latching, no power is required to keep them in the selected position. That saves power usage and it's why I only need a momentary switch. I bought them for $4.66 each from Digikey. Here's the link.

Here's the guts of the thing.




To protect the circuit board I found a near perfectly sized holder.


When the van is sitting and not running the radio is dark. If I flip the switch to "House" the radio lights up now being powered by the house battery. It will stay powered from the house battery until I either flip the switch to "Van" or start the van. When I start the engine the radio automatically switches back to the van battery. That way I don't have to worry about switching the radio back to van and since it's a momentary switch I can never leave it in the wrong position. A rather bad habit of mine.

Here's the diode I use to stop switch selected coil voltage from back feeding to the starting circuit.


After I got everything wired up it actually worked the first time. Surprised the hell outta' me. I'd wired up House and Van backwards on the switch but that's easy to fix. Just rotate the switch 180 degrees.

[Ford_6L_E350]

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

On my 2004 van, anyway.

I really like your relay system with automatic reset. Very clever.

Mike