Can I combine ignition/power wires for an AM/FM radio?

patrolcarr

Petty Officer 3rd Class
Joined
Apr 13, 2003
Messages
96
Hello all. I have a quick question:-I'm about to install a simple AM/FM CD player on my boat(Jensen). As far as the wiring goes, there appears to be two wires for positive(+), one directly to the battery, the other to the ignition. Can I bypass the ignition and combine it with the other positive(+)? Reason being is that I have an hour meter that engages when I switch the ignition on and dont want it clicking away because I want to listen to my radio. I dont want my engine showing more hours than it really has. Thanks.Pat.
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,758
Re: Can I combine ignition/power wires for an AM/FM radio?

Certainly. 12 Volts is 12 Volts whether it passes through a switch or not.
 

Gone

Petty Officer 1st Class
Joined
Aug 28, 2005
Messages
389
Re: Can I combine ignition/power wires for an AM/FM radio?

Be aware that without interupting the ignition line while you're away, the radio will probably drain your battery. I'd at least suggest an accessory dash switch for the ignition line.<br /><br />CD
 

rottenray6402

Ensign
Joined
Jul 27, 2004
Messages
923
Re: Can I combine ignition/power wires for an AM/FM radio?

All of the boats I have owned have been wired so the radio and for that matter almost all of the accessories will work with out the ign being on. In an older ign system that has points you never want to leave the key on for extended periods of time anyway or you may crisp the points.
 

Silvertip

Supreme Mariner
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Sep 22, 2003
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28,758
Re: Can I combine ignition/power wires for an AM/FM radio?

The radio has an on/off switch. Why add another. If he forgets to turn the radio off he's likely to forget to turn off the dash switch as well. As RottenRay (love that name) says, most accessories operate independent of the ignition switch anyway. If the radio is to retain the current time and memory presets it needs a constant on source as well.
 

Boatin Bob

Lieutenant Commander
Joined
Sep 24, 2001
Messages
1,858
Re: Can I combine ignition/power wires for an AM/FM radio?

As Crusty says it will drain the battery even if you turn it off, the display will still be on, you either need to remove the one 12v source or if it has a removable face plate, take that off and you won't have the problem. (this is from personal experience, been there and done that)
 
D

DJ

Guest
Re: Can I combine ignition/power wires for an AM/FM radio?

THe radio has two positives because one is for the station memory presets.<br /><br />If you don't mind losing your presets everytime you turn the ignition off, leave one + off.<br /><br />The "keep alive" memory draw is almost immeasurable.<br /><br />Your car/truck has allot more "keep alives" that that radio and that battery doesn't go dead.
 

patrolcarr

Petty Officer 3rd Class
Joined
Apr 13, 2003
Messages
96
Re: Can I combine ignition/power wires for an AM/FM radio?

SO, if I remember to turn the radio off, the battery should be ok? Right? When Crusty Dude mentioned killing the battery, was he implying IF I left the radio on? Thanks for all the help guys.
 

Boatin Bob

Lieutenant Commander
Joined
Sep 24, 2001
Messages
1,858
Re: Can I combine ignition/power wires for an AM/FM radio?

No....turning the radio off is not enough. Again there are 2 positive wires, the one is left attached to 12v all the time (in a car) and all this does is keep your memory alive, radio station presets, bass/treble settings, etc with very minimal power drain. The other 12v line is meant to be switched at the ignition because it handles the bulk of the power requirements. Even if you turn the radio off the display will stay on and after a time (maybe a week) it will drain your battery, it did to mine) the solution is to either remove that 12v through some kind of a switch or as I mentioned before if it has a removable face plate take it off (this is what I do)when finished using it and that will solve the problem. I've never seen anyone wire it to their ignition switch as most don't have an ACC postion like cars and you don't want to leave the ignition turned to on either (except while running)
 

patrolcarr

Petty Officer 3rd Class
Joined
Apr 13, 2003
Messages
96
Re: Can I combine ignition/power wires for an AM/FM radio?

Thanks Bob, that clears alot up. The radio I have does have a removable face plate, so there is my solution. Thanks alot for all the response. Another problem solved via I-Boats. This site is priceless.
 

waterinthefuel

Commander
Joined
Nov 15, 2003
Messages
2,726
Re: Can I combine ignition/power wires for an AM/FM radio?

You got it buddy. If you just remove the faceplate your problems are solved. Batteries go dead in boats when they aren't attached to any accessories. The current draw of your radio on off is next to nill, so just do what you said your problems are zero. Enjoy the tunes!!
 

Speedwagon

Petty Officer 1st Class
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Jul 5, 2005
Messages
389
Re: Can I combine ignition/power wires for an AM/FM radio?

I would probably add though, that if your boat is going to be in storage for awhile, that you should disconnect the battery. The slow drain from the radio memory might be enough to kill the battery in a few months.<br /><br />I put a '99 car in storage for 3 months once, battery attached, and it was dead after 3 months. Granted, it has a few more memories in it, but it was enough to kill the entire battery in only 3 months.<br /><br />But for normal use(at least once a month), that memory won't do much harm to a good battery. It will become apparent though, when the battery needs changing(as the memory will have more of an effect).
 

jlinder

Lieutenant Junior Grade
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Jul 5, 2004
Messages
1,086
Re: Can I combine ignition/power wires for an AM/FM radio?

Speedwagon,<br /><br />Keep in mind that in a car you also have the car computer with a lot more memory to keep alive.
 

Rob454

Chief Petty Officer
Joined
Oct 9, 2005
Messages
508
Re: Can I combine ignition/power wires for an AM/FM radio?

Someone may of said this but one of the + is for power the other is for memory. Youll loose your settings everytime you disconnect the battery.<br />I got mine wired to the battery. Im not really worried about presets. There are so few stations to get that throwing in a CD is easier.<br />ROb
 

Gone

Petty Officer 1st Class
Joined
Aug 28, 2005
Messages
389
Re: Can I combine ignition/power wires for an AM/FM radio?

Modern radio circuit design uses the battery wire (industry coded "yellow")as more than just the memory line. In fact it carries most of the power for the radio and is fused 7-15 amps. The "red" ignition wire is really just an ignition "sense" wire that merely wakes up the radio when the red wire sees +12V. The sleep current is very low (on the order of .003-.006 amps) with the red wire unactivated.<br />I always wire my personal and customers radios with a separate ignition/Acc switch, so I had to prove Bob's theory to myself. He is correct! For the Panasonic and JVC products, removing the faceplate works as well as a separate ignition/Acc switch. <br /><br />CD
 
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