Full time power to radio
 

Has anybody ever wired in full time power to the radio in our trucks? Would this just drain my battery every night? Maybe put a switch on it so you could use the radio with out the key in the ignition. I like to be able to listen to music while working on the truck or whatever, it'd be nice not to need my keys. Could I just tap the full time power in the cab into the ign. power in the radio? I'm not the best electrician so some advise would be nice.
Pete

Depends on the radio my fancy hightech radio drains the battery overnight my dads old radio didn't both where wired the sameway his new one got wired onto the ignition and my new one will be

Depends on the stereo most can be turned completely off. I always wire my radios to run without a key, but I have a stereo that can be turned off so the only power it draws is for clock and settings. I just run a wire with a 10 amp fuse from the battery to the radio.

:fire2: Quite simple to do but no matter how careful you are you will forget to turn it off .

Have a dead battery at the worse time.

Either get power from the fuse block or run direct from the battery.

X2 on "it depends on the radio". I had a radio in my 4Runner wired to constant power and it would drain about 30-40 mA even when off. That was enough to kill the battery if it sat for about 2 weeks. I swapped to a different radio and it works fine with constant power. So what you can do is rig up an ammeter in series with the battery and see what sort of current draw you have now with the key off. Then connect up the radio and see if the draw changes significantly.

Would it hurt anything to run a wire from the battery through a switch in the dash and splice into the ign. power to the radio? That way it would come on with the ignition or if I flip the switch. I figure there would have to be something wrong with that but annoyingly I'm not that good with electrical yet.

You may find that turning that switch might turn on other things on that same circuit. You could add a diode to block the back feed but then that would drop the voltage to the radio in normal operation. Best bet would be to stick a relay in there, feed the relay coil with switched and constant power (via your switch), with a blocking diode in the switch power lead, then send the battery power though the relay to the radio. Of course, if you forget and leave the switch on, that relay is pulling about 0.1 amps. As is, the radio should turn on with the key in the ACC position.

I'll probably just run a battery wire through a lighted switch on the dash so I know if its on and forget about ign. power.

Well I just finished wiring the switch up. It works fine, except that it doesn't "remember" what it was doing before I shut it off, only if I leave it off for more than a couple seconds. If I shut it off for more than about 5 seconds and turn it back on it just goes to the clock where its off. I know the red wire going to the stereo is the constant hot wire that I presume is what keeps its memory, I didn't mess with this wire, just the fused yellow "ign." wire.

Best thing you can do is take a spst toggle switch or the equivalent, solder a wire off one leg from the switch (doesnt matter which one) to the yellow or constant power wire behind the stereo on the harness. The other leg on the switch gets soldered to the red wire or ignition turn on wire also behind the stereo. Make sure the stereo is wired back to normal before you add this switch. This way, the stereo can still retain its memory function with all the saved presets, but also turn on with the flip of the switch AND turn on normally with the key in the ignition. While the truck is off, and with the switch flipped with the radio on, it will only provide power to the radio and will not send power to anything else, so you dont have to worry about other components on the dash drawing power. Hope this helps.

If you did a SPDT (single pole, double throw) switch, you could wire the center terminal to the radio power connection, then wire the one side of the switch to the constant power feed and the other side of the switch to the switched power feed. That way with the switch in the constant power position, you can turn the radio on any time (and you are only feeding power to the radio). Then flip the switch the other way and you have the normal switched power mode.

Sorry, I got it all figured out and it works great now. I guess I spliced into the constant hot wire instead of the ign. power. I was going off of the color coding from my old 87 when I replaced the stereo, turns out that was stupid. 5 minutes with the multi tester and got it all figured out, except how the hell my switch worked before. I just ran some 14 gauge wire through a 10 amp fuse, through the grommet in the firewall where wires go to the ECU, then to a lighted rocker switch in the blank panel then to the ign. wire. Works perfectly, and keeps its memory now.

Sounds a lot like my '85 wiring. The PO had hacked things up pretty bad. I ended up abandoning all but the speaker wires and ran my own power and ground wires for the radio.