How do I maintain auxillary power when cranking the starter?

downfall21 · Post by **downfall21** » Tue Jan 31, 2006 4:53 am

Is it even possible? When the kids are watching a movie and I go to start the car everything shuts down for 3 seconds. This is enough time to make the DVD player and screens shut off. Then I have to turn everything on again. It is getting annoying. Is there any kind of circuit or relay that can be added to fix the issue?

joatmon · Post by **joatmon** » Tue Jan 31, 2006 5:12 am

Where are you currently getting power for the DVD player from?

GMJAP · Post by **GMJAP** » Tue Jan 31, 2006 5:12 am

I don't know where you're puling power for the DVD system, but joatmon posted an easy how-to on making the rear console power outlet on all the time: http://forums.genvibe.com/zerothread?id=6403You might also try browsing the threads on retained accessory power- just search on "retained"Edit - always a little weird when someone else posts at the same time - especially when you mention them in your post!

joatmon · Post by **joatmon** » Tue Jan 31, 2006 5:26 am

slowpoke Some cars I've had, the starter sucks so much current that the voltage everywhere drops when the starter is turning. Depending on the DVD player and the extent that the voltage drops when starting the Vibe, it is possible that the only way to solve the problem would be to get a seperate battery to power the DVD player. I have never paid attention to how much the voltage drops in my Vibe when I start it, so I can't say if that is even a factor. Does the DVD player have a spot for internal batteries, and if so, does it help if there are batteries in there?

downfall21 · Post by **downfall21** » Tue Jan 31, 2006 5:31 am

I did a stacked iso install (CD and DVD units both in dash) so basically the cdplayer, dvd player and video screens all get their power from the switched power wire in the factory stereo harness. The problem only happens when starting the car.When you shut the engine off and switch to accessory it stays on.I found this unit made by PAC PAC-TR7.It looks like it has an instant on with a delayed power off of up to 4 mins.It only supports 2amps on the output though. So I would need to wireit into another relay. As for the voltage drop. Maybe I should add a 1/2 farad capacitor into the line. That should keep the voltage from dropping.Do you think this would work?Another thing I noticed. I am getting alternator whine no matter where I ground the dvd player and the monitors. The CD player is fine. It only affects the other units. Anyone else have that issue?

theangrydwarf1 · Post by **theangrydwarf1** » Tue Jan 31, 2006 7:00 am

A 1/2 farad cap should supply enough power, depending on how many watts your system is using. A 1/2 farad cap will handle about 500 watts, any more than that and I would consider a 1 farad cap. The cap may also eleminate the whine. If not try and find an in-line filter of some sort.

downfall21 · Post by **downfall21** » Wed Feb 01, 2006 4:47 am

This wouldn't be used to support the amps. This is strictly to stabilize the power to the source units and monitors during car startup.

Mase · Post by **Mase** » Wed Feb 01, 2006 4:53 am

The acc power is designed to cut off during cranking in order to provide max power to the starter. If you want the dvd player to stay on while starting, you'll need to connect its power wire to a constant 12v supply and connect it's remote/trip wire to a lead that's on even when starting. Some examples are the ECU wire or gauge wire.There's a trade off though. You'll only be able to operate the dvd when the key is in the 'on' position.

Jahntassa · Post by **Jahntassa** » Wed Feb 01, 2006 8:20 am

If you get a couple of large diodes, or even a relay, probably... what you can do is take power from the ACC on the back of the radio, then power from the Ignition wire in the ignition harness, run them together using diodes, and then power your DVD off that.. I need to do it with my computer and if I can ever stop being lazy, i'll actually do it and post something up about it.Mase is right, the ACC line is actually turned off during starting for the reason he supplied. As annoying as that is....Also, the cap is probably a bad idea. They aren't meant to be completely depleted and recharged constantly. Yes...pull power during hits (for subs), but I think for your purpose it would end up killing the cap pretty quickly.. That's only a thought though, and could be wrong

joatmon · Post by **joatmon** » Wed Feb 01, 2006 8:33 am

Quote, originally posted by GMJAP Â»You might also try browsing the threads on retained accessory power- just search on "retained"Perhaps a variant of jeffgtx's window RAP mod in http://forums.genvibe.com/zerothread?id=16904 would do the trick.

MatrixPC · Post by **MatrixPC** » Thu Feb 02, 2006 1:48 am

use the circuit attached.You can use "OUT" to control the relay that can be hook directly from the battery or where ever you currently use.

Attached files

Jahntassa · Post by **Jahntassa** » Thu Feb 02, 2006 10:47 am

MatrixPC posted exactly what I was trying to suggest.

How do I maintain auxillary power when cranking the starter?

How do I maintain auxillary power when cranking the starter?

Re: How do I maintain auxillary power when cranking the starter? (downfall21)

Re: How do I maintain auxillary power when cranking the starter? (downfall21)

Re: How do I maintain auxillary power when cranking the starter? (GMJAP)

Re: How do I maintain auxillary power when cranking the starter? (joatmon)

Re: How do I maintain auxillary power when cranking the starter? (downfall21)

Re: How do I maintain auxillary power when cranking the starter? (theangrydwarf1)

Re:

Re: How do I maintain auxillary power when cranking the starter? (GMJAP)

Re: How do I maintain auxillary power when cranking the starter? (joatmon)