Radio install wiring question

[Toyelectroman]

Install a new JVC stereo for the boat and was wondering how everybody is wiring the 12 volt constant wire. Currently it is tapped into the ignition wire and the issue is i usually turn the battery switch off when i put the boat back on the trailer. Which wipes out all the settings on the radio, so do i just run a dedicated wire to the battery? Would i need to worry about the radio draining the battery?

 

[tpenfield]

Install a new JVC stereo for the boat and was wondering how everybody is wiring the 12 volt constant wire. Currently it is tapped into the ignition wire and the issue is i usually turn the battery switch off when i put the boat back on the trailer. Which wipes out all the settings on the radio, so do i just run a dedicated wire to the battery? Would i need to worry about the radio draining the battery?

I just hooked up a new Kenwood Receiver and had to go through the wiring, etc. . . .

Was there an old unit installed, or are you installing from scratch?

The stereo needs constant power to keep the settings and this is how most stereos are installed, with a direct connection to the battery. The same will go for other things, like the bilge pump. It will not run the battery down much. So, go ahead and hook it up that way.

 

[Toyelectroman]

Replacing an old Boss head unit

 

[gm280]

If you are running a dedicated wire to the battery, make sure it is fused or circuit breakered as well. While the chances for this to short is really remote, you just never know. And as far as the battery being run down, that really depends on how much the memory circuits are drawing and the length of time between usage. Even a minuscule draw of current will take the battery down if it is left for a long period of time. JMHO

 

[tpenfield]

There is a color code standard for the wiring that the previous unit, hopefully, adhered to. The yellow wire is the constant power. The red wire is the on/off wire to power the unit. You can Google the color codes for the wiring

 

[gm280]

It sure seems odd that in today's electronic market that so many stereo/radio manufactures don't use EEPROM circuits for memory and stations. Once you program them in, they are electrically burned into the memory circuitry and remain there until you change them. So there would be zero need for any battery connected forever. As for the clock functions, a little lithium ion nickel size (CR2030, etc.) battery would solve that issues as well, for years. All that is needed is for the crystal oscillator to state running to keep time. That would be a few nano-amps at best. JMHO

 

[bruceb58]

The radio in my pontoon boat has flash memory to store the presets. It also has a switch that is wired to turn on to power the radio and I would do the same thing for any new radio installs.

I would never run an "always on" wire to the radio. I would just wire both the yellow and red wire to a toggle switch.

 

[Jcris]

In my experience, there's usually an unswitched hot wire somewhere. Check the fuse panel. You could add a fuse to an empty/unused spot and just jumper the incoming hot over to the new fuse location. An inline fuse would also work. Most radios will be fused on the back of the head unit

 

[muskyfins]

Wired my Kenwood receiver over the weekend. I also do not run the constant power wire. My boat is kept in a slip and I want to ensure there are no unneccesary drains on the batteries in case the bilge pumps are needed. (I do not have continous shore power) Some of the newer higher end head units use EEPROM.

 

[bruceb58]

In my experience, there's usually an unswitched hot wire somewhere. Check the fuse panel. You could add a fuse to an empty/unused spot and just jumper the incoming hot over to the new fuse location. An inline fuse would also work. Most radios will be fused on the back of the head unit

And then when you switch off your main battery switch, that constant voltage disappears anyway.

 

[dennis461]

duplicate post :-(

 

[dennis461]

How is your bilge pump wired?
My bro's boat has a constant feed to bilge pumps separate breaker fed straight from battery #1 (bypasses the #1-#2 big red battery selector switch and bypasses the main panel DC input breaker).

So when the boat is downpowered , we switch off everything except that particular breaker.

My boat is setup differently, OFF is OFF. I would have to run a new feed from battery to keep the radio memory alive.

By the way, the keep alive memory probably draws so little power, you could not measure it with many multi meters.
(and much much less than a five second run of the bilge pump).
I doubt you would drain any boat battery connecting it.

 

[bruceb58]

I doubt you would drain any boat battery connecting it.

If the keep alive current is 50 mA, that would be 1.2A/day. If you have a 70AH battery, you would discharge the battery to 50% in 30 days.

 

[Jcris]

I wonder how much current it takes to keep it alive

 

[dennis461]

My example,
Namsung America model MXD40 (with pretty nautical flags on front)
Keep alive only, 4.1mA
Keep alive and display showing time of day 114mA
Radio on volume all the way down 550mA.

My radio is off most all the time.
I simply hit the re-search function when I turn it on (may not be an option if your Admiral objects).

 

[bruceb58]

My example,
Namsung America model MXD40 (with pretty nautical flags on front)
Keep alive only, 4.1mA
Keep alive and display showing time of day 114mA
Radio on volume all the way down 550mA.

My radio is off most all the time.
I simply hit the re-search function when I turn it on (may not be an option if your Admiral objects).

Is that something you measured? I have measured auto stereos, but not in awhile, and they were a LOT more than that.

 

[dennis461]

Is that something you measured? I have measured auto stereos, but not in awhile, and they were a LOT more than that.

Measured today on my boat with the AM/FM radio model I posted (going fishing tomorrow so boat cover is off, engine started OK alternator OK, starter OK, raw water pump OK.

My concerns are more about on-the water battery drain. I mean, who cares if the battery goes dead at the dock or driveway.
I've measured my VHF and depthfinder before so I can leave both on while anchored.

 

[KD4UPL]

Killing your battery repeatedly, regardless of where the boat is at the time, is not good for the battery. In my experience a radio memory like that can drain a battery pretty far in a couple weeks. How often do you boat. I sometimes go 6 or 8 weeks between outings. I just had to redo any radio setting each time.

 

[Toyelectroman]

I ended up just wiring the 12 volt constant to the ignition wire so i will just learn to redo my settings each time

 

[Jcris]

A good safe choice