Is there a way to make a deck hold power on startup?

**rotarypower101** · 03-30-2006, 11:52 PM

Is there a way to make a standard aftermarket car deck not turn off and back on “as if power was cut from the ignition line” at startup?

I am sure there is something out there like this I just need to know what it would be called and what the process/components are.

Would a cap work for something like this?
Is there a thread someone could lead me to that talks about such a thing?

**jprice02** · 03-30-2006, 11:57 PM

correct me if im wrong, but couldn't you just put a constant power to the remote wire on the back of the deck and just put a swith on it to turn it on and off yourself?

**Playerbeat** · 03-31-2006, 12:09 AM

yes what you want to do is hook up 12v constant power(yellow) to the Accessory wire(red one). Make sure you turn off your deck or your battery will die.

**rotarypower101** · 03-31-2006, 01:27 AM

I still want it to operate in the standard way for the ignition to turn the unit on and off, but….say if you have the stereo running with the car off (acc on) and click the key over to start, the stereo would not cycle off and then back on.

I know some ignitions do not allow this as they sweep past off position from acc and then into engine crank position, but I think foreign cars (at least the ones I know of) like mine do not, and sweep from off to acc to start.

I am fairly sure this is possible, and that the problem is the drain on the system at crank, draws enough current to turn the stereo off as if power were cut.

I have mistakenly half turned over the engine and then while the engine was still in a expansion stroke but not started yet turn the key and start the engine, and this did not stop the stereo from continuing to play as it usually does at crank.

I am right to assume most if not all cars work in this way correct, where at crank if you are listening to a cd the player stops and comes back online after essentially restarting from off position?

I know my electrical system is sufficient, as I am using a newer red top optima battery with plenty excess CCA and the stereo is stock except for the HU.

Am I making this clear enough to relay what I am asking?

I just don’t want the stereo to shut off while changing the key position from acc to starting position while the engine cranks.

**Playerbeat** · 03-31-2006, 01:48 AM

Oh ok, yea a capacitor would work, but it would have to be a big one. You should probably go with some kind of delay circuit. Maybe something like this http://www.electronickits.com/kit/co...lec/ck1614.pdf

**Wiredwrx** · 03-31-2006, 02:19 AM

Originally Posted by rotarypower101

I still want it to operate in the standard way for the ignition to turn the unit on and off, but….say if you have the stereo running with the car off (acc on) and click the key over to start, the stereo would not cycle off and then back on.

I know some ignitions do not allow this as they sweep past off position from acc and then into engine crank position, but I think foreign cars (at least the ones I know of) like mine do not, and sweep from off to acc to start.

I am fairly sure this is possible, and that the problem is the drain on the system at crank, draws enough current to turn the stereo off as if power were cut.

I have mistakenly half turned over the engine and then while the engine was still in a expansion stroke but not started yet turn the key and start the engine, and this did not stop the stereo from continuing to play as it usually does at crank.

I am right to assume most if not all cars work in this way correct, where at crank if you are listening to a cd the player stops and comes back online after essentially restarting from off position?

I know my electrical system is sufficient, as I am using a newer red top optima battery with plenty excess CCA and the stereo is stock except for the HU.

Am I making this clear enough to relay what I am asking?

I just don’t want the stereo to shut off while changing the key position from acc to starting position while the engine cranks.

There is another way. What you need to do is get your voltmeter out, and check each fuse in your fuse box. Some switched fuses remain on when you start the car, and some don't. Just run a wire from the fuse that remains on to your radios acc wire, and you should be good to go.

Michael

**ArcticGenes** · 03-31-2006, 03:45 AM

Best route is what has been previously discussed. Connect the acc wire from the deck to the battery line then either be sure to turn the deck off. If you are worried about battery draining then get a switch.

**scott_fx** · 03-31-2006, 04:10 AM

Originally Posted by ArcticGenes

Best route is what has been previously discussed. Connect the acc wire from the deck to the battery line then either be sure to turn the deck off. If you are worried about battery draining then get a switch.

best route? i think wiredwrx has the best route, it doesnt involve human interaction.

another thing would be to setup a relay and delay. when the acc line hits 0volts the relay would switch to constant power for a few seconds. if the acc line doest get power in few seconds then the stereo would shut off automatically.

**rotarypower101** · 03-31-2006, 12:33 PM

Originally Posted by Wiredwrx

There is another way. What you need to do is get your voltmeter out, and check each fuse in your fuse box. Some switched fuses remain on when you start the car, and some don't. Just run a wire from the fuse that remains on to your radios acc wire, and you should be good to go.

Michael

Beautiful and simple!

You really are a Jack of all trades around here aren’t you!
Thanks for taking the time to help us inexperienced guys.

Are there some unforeseen reasons why these are wired like this from the factory?

I will see if I can’t make this work for me.

Any advice as to which circuit would be best to tap into?
I should probably go with the highest rated circuit in the fuse box right?
I am taking a guess the highest rated one would have the least effect on exsisting systems right?

**greenman100** · 03-31-2006, 01:01 PM

Originally Posted by rotarypower101

Beautiful and simple!

You really are a Jack of all trades around here aren’t you!
Thanks for taking the time to help us inexperienced guys.

Are there some unforeseen reasons why these are wired like this from the factory?

to give the starter the maximum output from the battery.

some stuff, like the engine computer, must stay on through cranking.