Wiring head unit and amplifier to van battery and house battery

Hello,

I just purchased a 2003 dodge sprinter and I am looking to see what it would look like to build a system where I can run speakers in the back of the van and the front while driving normally and while parked running off the house batteries in the back. I saw a wiring diagram a while ago on this forum that seems to look pretty good, but I was wondering how the accessory wire would be run so that it could turn on and off with the key, but then be able to turn on when switched to the house batteries. Has anyone had any experience with this? I am also just considering running a separate head unit and speakers in the back to run off the house batteries as that seems like it might be easier?

Thanks!
 

Attachments

BrennWagon

He’s just this guy, you know?
There are a number of ways to accomplish this, the most straightforward way is to run main power to the radio system from the aux battery and use the OEM signal wire to turn it on while driving, then add a switch to bypass the signal wire from the aux battery. This is essentially what I did and it works flawlessly and I never have to worry about draining the main battery. You’ll want to mount an aux fuse/relay box for the aux circuits. I attached mine to the outside of the back of the passenger seat base and in the almost year that it’s been in place I’ve had zero problems but I have great accessibility if a fuse or rely goes bad.
 
There are a number of ways to accomplish this, the most straightforward way is to run main power to the radio system from the aux battery and use the OEM signal wire to turn it on while driving, then add a switch to bypass the signal wire from the aux battery. This is essentially what I did and it works flawlessly and I never have to worry about draining the main battery. You’ll want to mount an aux fuse/relay box for the aux circuits. I attached mine to the outside of the back of the passenger seat base and in the almost year that it’s been in place I’ve had zero problems but I have great accessibility if a fuse or rely goes bad.
Thanks for the reply! That seems like a good solution. Do you have a wiring diagram or would you mind quickly drawing one out so I can better understand the setup? Also If I understand correctly, with this setup, the audio system does not rely on the vehicle's battery at all for its power? My only concern might be that I don't want to drain the house battery from just driving and listening to music, however, maybe this could be mitaged by adding the dc to dc charger while you drive. And did you run an amplifier with your setup or just the head unit?

Thanks!
 

borabora

Well-known member
I think what you want to do isn't very difficult as described by BrennWagon above. But I think what you want sound-wise might be different while driving versus while sitting inside. I find that to overcome engine and road noise I want boosted bass and attenuated highs when driving. I also want sound to appear to come from the front with a little from the back and the balance shifted to the right. When not driving I want a more neutral sound and possibly coming from a different direction. In other words, consider adding another system instead. If you find yourself mostly streaming from your phone then consider a low cost BT enabled 12/24V amp and some automotive speakers. But if you want the additional benefit of being able to take the sound outside consider one or two BT speakers. You can always mount them to be removable and with charging cables at those locations.
 
I think what you want to do isn't very difficult as described by BrennWagon above. But I think what you want sound-wise might be different while driving versus while sitting inside. I find that to overcome engine and road noise I want boosted bass and attenuated highs when driving. I also want sound to appear to come from the front with a little from the back and the balance shifted to the right. When not driving I want a more neutral sound and possibly coming from a different direction. In other words, consider adding another system instead. If you find yourself mostly streaming from your phone then consider a low cost BT enabled 12/24V amp and some automotive speakers. But if you want the additional benefit of being able to take the sound outside consider one or two BT speakers. You can always mount them to be removable and with charging cables at those locations.
Thank you Borabora for the reply! That is a good point and I will consider that as well. Certainly using the portable BT speakers would be the simplest/most portable solution. Perhaps if I go with the first route of running the regular sound system while parked off the house batteries, I was thinking about adding a 4channel amp to that system to be able to run another 4 speakers in the back so that it would hopefully sound good whether you were in the front or the rear.
 

BrennWagon

He’s just this guy, you know?
Thanks for the reply! That seems like a good solution. Do you have a wiring diagram or would you mind quickly drawing one out so I can better understand the setup? Also If I understand correctly, with this setup, the audio system does not rely on the vehicle's battery at all for its power? My only concern might be that I don't want to drain the house battery from just driving and listening to music, however, maybe this could be mitaged by adding the dc to dc charger while you drive. And did you run an amplifier with your setup or just the head unit?

Thanks!
@gltrimble nailed it on the wiring diagram. My aux battery system is setup with a very simple battery to battery charging relay.
 

gltrimble

Well-known member
@gltrimble , Thanks for drawing the diagram out! I will do some research on parts to buy now and keep you all updated! Thanks again for all the help!
Simple automotive relay is all that is required. On my Pioneer stereo the yellow wire is 12 volt power and the red wire is the 12 volt ignition signal. Colors may not be the same on all radios. Relay link below. I bought a rocker switch labeled “Stereo” but have not yet changed out the “Zombie” switch which currently powers the stereo.


3D3CC254-E144-424C-9B72-1D927F785F0C.jpeg
A8BFA860-6EC0-4002-927B-E4949A675865.jpeg
 
Simple automotive relay is all that is required. On my Pioneer stereo the yellow wire is 12 volt power and the red wire is the 12 volt ignition signal. Colors may not be the same on all radios. Relay link below. I bought a rocker switch labeled “Stereo” but have not yet changed out the “Zombie” switch which currently powers the stereo.


View attachment 171762
View attachment 171763
Thanks for the link! I like the "zombie lights" switch! I suppose that if I were to add an amp to this system, I could just wire it to the house battery and have the radio turn it on and off and wouldn't need a separate switch making that part of the install also pretty straightforward. Also, just to clarify, when you are running the wire from the house battery to the yellow wire, and then switch to the yellow 12v wire, did you just tap both of those wires into the one yellow 12v wire?
 

gltrimble

Well-known member
Thanks for the link! I like the "zombie lights" switch! I suppose that if I were to add an amp to this system, I could just wire it to the house battery and have the radio turn it on and off and wouldn't need a separate switch making that part of the install also pretty straightforward. Also, just to clarify, when you are running the wire from the house battery to the yellow wire, and then switch to the yellow 12v wire, did you just tap both of those wires into the one yellow 12v wire?
Yes, the ignition lead on the radio rarely pulls any significant load. Just acts as a signal to turn on. The radio is always energized.
 

kper

Member
I just use a switch and it always runs off the house battery. Easy enough to click the switch when I want tunes and never a possibility of draining the starting battery.
This is what I did as well. Switched power also supplies the amp 'turn on' signal. With the audio control amp (and I'm sure others), I can toggle the input to be the speaker level input from the mbux head unit or BT direct from my phone (driving vs stationary, respectively).

And dang it gltrimble -- I thought my zombie lights idea was original. Wife made fun of the front light bar only being useful in a zombie apocalypse and then I found the zombie logo. Apparently it is not original content!

IMG_5987.jpgIMG_5987.jpg
 

Attachments


Top Bottom