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chrysler radio drains battery?

4146 Views 9 Replies 6 Participants Last post by  keithsketchley
hey my aunt and uncle have a convertable idk exactly the year i think its a sebring maybe not im not sure i kno this prob doesn't help at all not knowing hahaha but anyway he called me tonight saying that if the radio fuse is in it will drain the battery even when its running but u take it out and the battery is fine he said his mechanic said its a short somewhere between the radio and the speakers?? anyone ever have this problem be4??
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Older radios use a bit of current to keep memory of station pre-selects alive, that small amount will eventually drain the battery, I hope newer ones have non-volatile memory.

Your message isn't coherent on when the problem occurs. You need to parse into sentences and check for contradictions before posting.

Draining the battery when running would indicate the charging system is not working - the ignition will drain the battery faster than a radio will. (Unless someone installed a monster sound system, in which case I would refuse to help the owner.)

The speakers are only energized when the ignition is in Accessory (for those vehicles that power the radio then) or Run.

I don't accep the mechanic's claim, he does not understand radio systems.

Perhaps the radio is staying on - check that it is off when the ignition switch is in the OFF position. Worn ignition switch mechanism could keep it powered.
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every time we turn the car off the radio is off

not sure why its doing this its only when the radio is on

if we take the fuse out of the fuse box and run it the car is fine battery stays charged and everytihng

as soon as we put the fuse back in to listen to the radio is when the battery starts to drain even while driving it
Hmmm. This is a tricky one. Is the radio a stock unit? Is the rest of the sound system a stock Chrysler unit, and is it the unit that came with the car from the factory?

I know if it's a non-stock system/crazy system it can sometimes be powerful enough to drain the battery even while moving. Usually that's only with very powerful systems with very large woofers/sub-woofers and the amplifiers to drive them.
no its a aftermarket radio its just its been in there since we bought the car i believe they bought it a few years ago

it has never done this till recently im going to pull it out and check all the connections tommorow
I'd guess that if you see no issue in the wiring, I'd get checking the battery and alternator. Most likely the battery is just getting down to the end of it's life and needs replaced. If that doesn't fix it, I'd check the alternator.
The mechanic is not a very good mechanic, as far as diagnostic skills.

Procedure: Measure the current draw on the battery, and its open-circuit voltage, with and without fuse installed, with engine off. Then measure battery voltage at idle. Current draw when off should be about 30mA or so. Battery should be about 12.5V with engine off, and 14V at idle. Radios only draw about 1mA or less of current for backup power, and typically only a couple of amps when running. So if running the car with the radio fuse installed can pull the battery down, it's NOT the radio.

Often there are other circuits on the radio fuse, such as the dome light, glove box light, or even one of the computers.

So the thing to do after the above steps is to leave the fuse in, but unplug the radio, and measure the current draw again. I'll bet unplugging the radio makes no difference. The mechanic needs to find out every circuit that is powered off that fuse, and unplug each device one at a time until the current draw drops. That will indicate what's really at fault.
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In many newer vehicles, the radio and other electrical accessories can be kept on for selectable periods after the ign key is turned off and until a door opens. This feature is controlled by the TIPM, CCN (cluster) or BCM. Battery power is always at the radio and the radio is switched on and off by communications bus logic commands. This could be problematic with an aftermarket radio.
The station presets in a Chrysler radio have been non-volatile since 1996, meaning that they will stay in memory after a battery disconnect. The clock is dependent on battery memory and has to be reset.
Display and faceplate illumination dimming may also be PWM (pulse width modulated like a fuel injector) by a driver in the CCN or BCM over the communications bus.
Nothing is simple any more.
You need to see how the radio has been wired in and if the radio may be made compatible with an interface. The installer may not have had the know-how or materials:
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My concern - someone screwed up the wiring to the new deck when it was installed. That's the first thing I'd check. It's not that hard to install one properly, but it's a piece of cake to do it wrong and get wires connected improperly or shorting out because Joe Weekend Warrior figures it's ok if he cuts off the factory connectors and twists the wires together with only some scotch tape to insulate them.

There are other possibilities, like a faulty head unit or a problem elsewhere in the circuit, but I'd verify the deck was installed properly first. Could be the difference between draining batteries and an electrical fire.
Good point about other loads on fuse - check for an underhood light and a trunk light.
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