Radio drawing power when off

lostagain · July 15, 2011, 07:39:32 AM

There are a few things powered by 12 volt on my 5C. It is off the Vanner equilizer. It slowly sucks the batts down when parked. So I traced it to the radio. With meter in line, it shows 12v when the radio in plugged in, 0v when radio plugged off. I am doing this with the radio turned off. The radio is a late model Pioneer and works good. Is this normal? If so I will install a switch to turn all 12v circuits off when parked. Now I just pull the fuse.

Thanks,

JC

robertglines1 · July 15, 2011, 07:42:42 AM

Discovered same. was told it was to preserve memory etc.

luvrbus · July 15, 2011, 07:45:54 AM

Yep that is normal if no power then you have to reset everything on the radio over again ,it kills the battery in our Lexus in about 3 weeks it is a Pioneer system don't you love the modern electronics

good luck

belfert · July 15, 2011, 07:46:29 AM

All modern car radios draw constant power to preserve station presets and such.

This shouldn't draw down the battery quickly. Any car made in probably the last 20 years uses battery all the time for the radio and computer. A car can usually go weeks between starts so why shouldn't your bus with probably 4 times the battery power?

zimtok · July 15, 2011, 07:46:34 AM

Most current car radios have two power supplies, one for constant power and one that gets turned off with the ignition.
The one that requires constant voltage is keeping the clock going and the programmed preset stations setup. If you turn off the voltage to the "constant voltage" wire you will have to reset the clock and your preset radio stations.

.

Dang you guys are fast......

.

bevans6 · July 15, 2011, 07:56:51 AM

When I first installed my radio (Pioneer, what is up with that?) I didn't add a switch to simulate the ignition switch to put it in sleep mode. It drew a lot of power even when turned off. I added a toggle switch to the ignition switch lead, and it is a lot better.

Brian

belfert · July 15, 2011, 07:58:10 AM

Going along with what Zimtok said be sure the radio is wired properly so it isn't staying in full on mode.

I replaced my dash radio with a much better Pioneer, but I completely rewired with new speakers for the passengers and driver. I also ran power from the house side instead of the chassis so it can be run while camping. There is a main power feed and then an ignition switch. I use an abandoned dash switch to turn the radio on and off. Yes, it draws power constantly, but the radio in off mode would take months or years to flatten my 6 AGM batteries.

pipopak · July 15, 2011, 07:59:24 AM

If battery juice is going down at an abnormal rate you may have a problem somewhere else. Easiest way to test (but not guaranteed 100% effective) would be to wire an ammeter between the batteries and the coach. With engine off and everything off should read 0. If not, start pulling breakers until you find the one. Then test that circuit to pinpoint the offending piece. You will be surprised with the findings.

Van · July 15, 2011, 08:19:25 AM

In regards to the radio memory, I have been doing something like this since the newer radio's came out. You can fab a pig tale for a 9 volt batt to the memory lead once the bus batts are disconected, simple and inexspensive. Here just for example:
http://www.ecklerscorvette.com/computer-memory-saver.html

Hope this helps JC

Van

luvrbus · July 15, 2011, 08:42:56 AM

He is going through his Vanner they draw power in the standby mode also

good luck

Busted Knuckle · July 15, 2011, 08:55:20 AM

Quote from: luvrbus on July 15, 2011, 08:42:56 AM
He is going through his Vanner they draw power in the standby mode also

good luck

I've had several Vanner's that when they got old ran my batteries down with no loads attached to them at all! Once they were replaced the dead batteries went away. Shoot one driver left the batteries on and the bathroom light was on and the bus still started 8 days later. (before replacing that Vanner it'd kill the batteries in less than 8 hrs.)

So just for kicks and giggles try disconnecting the Vanner for however long it's been taking to kill the batteries and test them. If you still have plenty of power it's the Vanner sucking too much juice and needs replaced.

BK

lostagain · July 15, 2011, 10:10:37 AM

Thanks all you guys!! I have a much better understanding now. I can overhaul a Detroit, but I am still quite electricly challenged, to say the least

Another thing that was drawing off 12 volt is the brake controller circuit. I will look into that next. Must be a short that draws off the batts faster than the radio.

As for the radio, I had noticed that it lost its memory every time because I pulled the first fuse coming off the equilizer when parked at home in the shop. I see why now.

Thanks again, ever learning and fixing stuff,

JC

Len Silva · July 15, 2011, 10:37:53 AM

Quote from: pipopak on July 15, 2011, 07:59:24 AM
If battery juice is going down at an abnormal rate you may have a problem somewhere else. Easiest way to test (but not guaranteed 100% effective) would be to wire an ammeter between the batteries and the coach. With engine off and everything off should read 0. If not, start pulling breakers until you find the one. Then test that circuit to pinpoint the offending piece. You will be surprised with the findings.

If you don't want to use an ammeter, you can just connect a small light bulb in the battery circuit. If there is any load at all, the lamp will light. The smaller the lamp, the more sensitive it will be to small loads.

If you are working alone, as I often am, you can use an electronic sounding device (Sonarlert) in place of the lamp. It will sound off until the load is removed.

pipopak · July 15, 2011, 11:17:16 AM

Quote from: Len Silva on July 15, 2011, 10:37:53 AM
Quote from: pipopak on July 15, 2011, 07:59:24 AM
If battery juice is going down at an abnormal rate you may have a problem somewhere else. Easiest way to test (but not guaranteed 100% effective) would be to wire an ammeter between the batteries and the coach. With engine off and everything off should read 0. If not, start pulling breakers until you find the one. Then test that circuit to pinpoint the offending piece. You will be surprised with the findings.

If you don't want to use an ammeter, you can just connect a small light bulb in the battery circuit. If there is any load at all, the lamp will light. The smaller the lamp, the more sensitive it will be to small loads.

If you are working alone, as I often am, you can use an electronic sounding device (Sonarlert) in place of the lamp. It will sound off until the load is removed.

Please note that both Len and I failed to note that the battery has to be disconnected and the ammeter/lamp/sounding device wired in series between the battery and the rest of the installation.

buswarrior · July 15, 2011, 07:48:23 PM

An often overlooked power drain is the old PA amplifier, if it hasn't been stripped out.

I like that trick of putting the small battery into the memory circuit for the radio!

Thank you for sharing that!

The busnut who has a true master battery switch,
and uses it when the coach is in storage,
doesn't report run down batteries?

happy coaching!
buswarrior