Full time 12V wiring question for radio (1 Viewer)

[eleblanc]

I'm installing my two relays,

One is hook on Accessories in the fuse box and the other one on the "'on" position.

That will allow me to hook up the 24v to 12v converter on full time current from the battery and feed both relays. And at the same time use full time 12V to my radio wire that need full time current for those darn memory channels and radio setup.

BUT, i also have a kill switch, it cuts the wire from the negative of the battery to the frame. So if i close the kill switch i'm back to square one and loose everything on my radio.

SO, i decide to wire the negative or ground wire from the radio directly on the negtive of the battery. So i test the thing, program 2 channel on the radio, close the ignition, shut the kill switch, then turn the key back to accessories and to my surprise, everything hook up on the relay/accessores light up and Darn...even some 24V lights and other things, so i realise my radio must be acting has a 24V ground and if i try to start that puppy i'm going to blow this radio.

ANYHOW, am i lost?, or is this normal?, what should i do? stop using my kill switch? is there a way around this? I know i could just try to make sure the kill switch is always on before cranking it, but i know i will eventually forget this a blew the radio fuse. Could a second converter setup for only the radio fix this?.

Thanks!

 

[M John Galt]

Perhaps a small 12v gel cell or ni-cad battery just to power the radio. Recharge the radio battery with the normal 24-12 converter when running, and turn the converter on/off with a relay from the acc power source.

 

[eleblanc]

Perhaps a small 12v gel cell or ni-cad battery just to power the radio. Recharge the radio battery with the normal 24-12 converter when running, and turn the converter on/off with a relay from the acc power source.

The thing is that the red wire that require full time current is made of heavier gage then the other wires on the back of the radio, so it must draw its full current through that. How much a radio could take?5amp? depend alot on the speaker and amplificator setup. But 4 simple speaker is probably more then any battery can handle.

 

[M John Galt]

The thing is that the red wire that require full time current is made of heavier gage then the other wires on the back of the radio, so it must draw its full current through that. How much a radio could take?5amp? depend alot on the speaker and amplificator setup. But 4 simple speaker is probably more then any battery can handle.

The small 12v battery only powers the memory when the radio is 'off' and converter power is off. When the converter is on the radio works like normal and draws it's power from the converter while the back-up battery recharges.

 

[eleblanc]

My converter negative is grounded to the frame, what if i wire that directly to the battery.

 

[eleblanc]

Been thinking, and i think my ground (black) wire from the radio to the battery, and mostlikely the radio casing touching the frame is acting has a ground for the whole system. I will test this theory tonight.

So i guess my only option to have a fulltime current to the radio even with a kill switch will be to use a battery.

John, if i use a battery don't i have to feed the battery with 12V then from the battery to the radio, so that there is never any kind of power interuption?. If i wire it like that will the full power consumption of the radio going through the battery will eventually kill the battery? I'm not sure how i'd go on wiring this so the radio never have a power interuption.

 

[M John Galt]

The 12v battery is in parallel with the radio, the power does not go through the battery.

 

[Stone]

The kill switch that you have is I suppose to prevent theft of your vehicle? If so, it might be worthwhile to change that kill switch to disable the starter instead of disconnecting your battery bank.

You can't go from your 12V radio to the (-) terminal of your battery bank while it's disconnected from the chassis ground. THe current will flow in funny ways to find its way around. Let us know what you decide/find.

 

[eleblanc]

Yes that kill switch was to prevent theif to try to jump start it to the frame. I'll keep the kill switch as is but only use it while i'm storing the truck for the winter. I will install a other switch to prevent it to start, now i need to figure what wire should i cut.

I'll be installing a gps alarm locating system very soon. So on top of a kill switch if the trucks move more then 5 meters without the transponder disabling it, it will send a stolen alarm to the central and they will send police after it...isn't that cool or what? then gps alarm does have a internal battery so even if they cut wires it will send the alarm. I just need hints on were it would be real hard to find.

 

[JohnnyBoy]

you could keep the system you have if you insulate the radio from ground. i had to do this with my audi, it had a positive ground WTF. i blew up an old deck figuring that one out.

 

[bj40man]

Hello!

I have the exact same problem with a 12v radio on a 24v 40 series. What I figured and have not yet tried as it is not installed yet, is to hook the permanent power wire to a 9v battery. I figure if it only need power to keep memory going, then that should suffice.

What you guys think?

 

[Garry]

Hello!

I have the exact same problem with a 12v radio on a 24v 40 series. What I figured and have not yet tried as it is not installed yet, is to hook the permanent power wire to a 9v battery. I figure if it only need power to keep memory going, then that should suffice.

What you guys think?

I have been told to try the same thing. Haven't put to test yet. bj40man, try it and let us know how it works.