Radio drains battery

studders

Petty Officer 2nd Class
Joined
May 9, 2014
Messages
134
Good morning all. Question. What could be causing my radio to drain my battery. It’s a new battery. The boat is a 1989 Baja islander 190. I think it might be wired wrong but that’s why I’m asking. It has been like this ever since I’ve had it. Almost afraid to turn it off while we are just floating in the coves. Seems like the power is always on. I can turn the radio on even when the key is not turned on. I always have to make sure to power down the radio when we are done for the day and trailer it. Shouldn’t there be like a acc connection for the radio or have to turn the key back like you do in a older car so that it reserves the battery. Thanks for any info and help.
 

alldodge

Supreme Mariner
Joined
Mar 8, 2009
Messages
32,353
Most radios don't run off the key, they are hard wired. Also most radios don't draw enough to drain a battery over a few hours. Does it have a amp?
 

alldodge

Supreme Mariner
Joined
Mar 8, 2009
Messages
32,353
Are you sure its the radio draining the bat?
Other things can cause a drain, maybe the alternator or key switch is not fully shutting off.

If the ALT has a bad diode it will charge when running and cause a drain when off.
 

ahicks

Captain
Joined
Sep 16, 2013
Messages
3,274
Generally a radio CAN run a battery down, but it's going to take months, not hours.
A master switch on the battery the radio is connected to can solve that issue,
 

studders

Petty Officer 2nd Class
Joined
May 9, 2014
Messages
134
Are you sure its the radio draining the bat?
Other things can cause a drain, maybe the alternator or key switch is not fully shutting off.

If the ALT has a bad diode it will charge when running and cause a drain when off.
Yeah that was another possibility. I planned on changing out the alternator but was just getting some other thoughts before doing that. It is probably really old
 

alldodge

Supreme Mariner
Joined
Mar 8, 2009
Messages
32,353
Turn the battery switch OFF or disconnect it. Disconnect the orange wire from the ALT and make sure it doesn't contact anything. Reconnect the battery and then touch the wire back to the ALT post and see if you get a small spark. If you do then ALT is the issue

If no spark, with everything OFF, disconnect the battery positive cable. Touch the Bat cable back to the post and see if you get a spark
 

Ahall8799

Cadet
Joined
Apr 30, 2021
Messages
10
Good morning all. Question. What could be causing my radio to drain my battery. It’s a new battery. The boat is a 1989 Baja islander 190. I think it might be wired wrong but that’s why I’m asking. It has been like this ever since I’ve had it. Almost afraid to turn it off while we are just floating in the coves. Seems like the power is always on. I can turn the radio on even when the key is not turned on. I always have to make sure to power down the radio when we are done for the day and trailer it. Shouldn’t there be like a acc connection for the radio or have to turn the key back like you do in a older car so that it reserves the battery. Thanks for any info and h
If your boat has a battery switch for your electronics battery then just turn it off when your done boating. If it doesn't then install one between the electronics battery wires and the breaker/fuse box and the negative bus. I wasn't super clear if it will drain underway but if it is your electronics battery probably isn't connected to the alternator.
 

MRS

Commander
Joined
Jul 10, 2005
Messages
2,378
When radio shack was open I bought a switch that I hooked in to the wires that hooked into the battery for the radio and would shut off when we got home. Worked great for me.
 

poconojoe

Lieutenant Junior Grade
Joined
Sep 10, 2010
Messages
1,173
A lot of stereos have two 12 volt input wires. One is constantly hot in order to keep the clock and radio presets in memory. This could be the cause of your drain.

This happened to me once when the boat was in my driveway for a week or so.
Now I always turn the battery switch off. I checked to make sure there's no power at the radio when the battery switch is off.

I disconnected that wire on my radio anyway. I think it was yellow, if my memory serves me correctly.
 

studders

Petty Officer 2nd Class
Joined
May 9, 2014
Messages
134
Thanks for all the input. I was hoping to do these tests on the alternator yesterday but other things came up. Hopefully I can get to it today and give some feedback
 
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