Getting ready to install P4000. Couple of questions

Mark05KR · #1 03-07-2009, 02:14 PM

I am getting things ready to install an AVH-P4000DVD, along with the bluetooth adapter and HD Radio receiver. I will also being adding a switched backup camera so it can be turned on manually as well as when the truck is in reverse.

My plan is to get power for these devices from the electric trailer brake controller connector that I will never use. The wiring is already there under the steering column and the pigtail to plug into it came with the truck. This is a dedicated, 30 amp, fused circuit. I have tested the circuit and it is always hot, not switched through the ignition. The plan is use a relay on that circuit that will be switched on by the blue/white amp turn on lead from the HU, so the accessories will only be powered up when the HU is on.

So here are the questions.

1) Is there any problem getting power for the bluetooth, hd and camera from the same source? The amp draw will be far less than the 30 amps available.

2) Do these three accessories (and the relay) need to be individually grounded or can they all be grounded together?

3) Can I use the ground wire available on the pigtail to ground these accessories and the relay? The ground wire from the pigtail is rated to carry up to 50 amps.

Thanks for any advice you can provide.

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Mark05KR · #2 03-13-2009, 06:06 PM

Oh well. I guess I'll just have to do this and hope for the best. Wish me luck.

shaunakadub · #3 03-13-2009, 06:10 PM

Mark, sorry I can't help ya... but this thread is in a pretty quiet area... give it a little more time... there's a bunch of people on here that will be able to answer your question!

BlueFordMatt · #4 03-14-2009, 11:36 AM

ok bud, don't do that!
-you need to tap the reverse lights in your tail lights for the 12v power to your camera.
-HD radio, bluetooth, all will fit behind the deck and tap the constants off the factory harness. you might blow less fuses
-you can ground all of them together as long as you sand the metal that you are grounding to. make it shiney.I would personally get the pigtail and cut to the length of all the other grounds behind the deck and use a self tapper.

Mark05KR · #5 03-14-2009, 02:18 PM

Quote:

Originally Posted by BlueFordMatt

ok bud, don't do that!
-you need to tap the reverse lights in your tail lights for the 12v power to your camera.
-HD radio, bluetooth, all will fit behind the deck and tap the constants off the factory harness. you might blow less fuses
-you can ground all of them together as long as you sand the metal that you are grounding to. make it shiney.I would personally get the pigtail and cut to the length of all the other grounds behind the deck and use a self tapper.

Thanks for the reply, but I think I didn't explain the situation very well.

The camera will be powered by the backup light circuit. I also want to be able to turn the camera on when not in reverse, so that is why I need a separate 12v power source. Power will be switched between the 2 sources with a SPDT switch.

I am taking power from the electric brake controller circuit since it is not being used and is a dedicated 30 amp circuit. There is no real chance of blowing fuses since the devices to be powered will draw less than 10 amps. I am running the power through a relay, switched on by the HU, since the power lead from the electric brake controller circuit is always hot. The bluetooth and HD radio will only receive power if the HU is on. Also, the rear view camera will be turned off when the HU is turned off, even if I leave the SPDT switch in the wrong position.

The HU itself will be plugged into the factory radio harness. I got the proper wiring pigtails for that from Crutchfield. Plug and Play. There shuold be no need to provide any additional ground for the HU.

Now, the electric brake controller circuit and pigtail has a ground wire already supplied. This wire was designed to provide a ground point for an electric brake controller. The ground wire from the pigtail has to be connected to the body or chassis or frame somewhere so I should be able to run the grounds from my devices to this already grounded wire. The instructions that came with the pigtail indicate that this ground wire is rated for 50 amps, so it should be sufficient for a less than 10 amp load.

I hope this makes more sense than my previous post.

Low_e_Red · #6 03-14-2009, 09:27 PM

NO!

Power the cam by a switched ONLY! Then take the Purple/White wire on the 4000 and run it to a Black/Pink in the bundle coming from the driver floorboard (will have to lift up carpet, its fairly easy to find.) This will switch to the cam when truck is in reverse and give you the option to view it while moving.

All the accessories can be powered by the deck harness but I do recommend splitting them between the radio harness and the 12v powerpoint right next to it.

Mark05KR · #7 03-15-2009, 10:14 AM

Quote:

Originally Posted by Low_e_Red

NO!

Power the cam by a switched ONLY! Then take the Purple/White wire on the 4000 and run it to a Black/Pink in the bundle coming from the driver floorboard (will have to lift up carpet, its fairly easy to find.) This will switch to the cam when truck is in reverse and give you the option to view it while moving.

All the accessories can be powered by the deck harness but I do recommend splitting them between the radio harness and the 12v powerpoint right next to it.

Not really sure what you mean when you say 'power the cam with a switched only'. Are you saying run power from the switched relay directly to the camera with no switch?

The problem with doing that is that the camera will always be on, even when it is not needed. If there is a SPDT switch in the circuit, the camera will be turned on by the reverse lights circuit when the switch is in the normal position and off when not in reverse. The other switch position will power the camera when I want to use it when not in reverse. Don't really want to have the camera turned on 100% of the time when it will only be used 1% of the time.

Getting the power from the brake controller circuit (through a relay) should be the same as getting it from the power point without putting any extra draw on the power point circuit.

Mark05KR · #8 03-22-2009, 10:12 AM

OK. NOW I understand what you guys were trying to tell me.

There should be no relay interrupting power the accessories. The bluetooth adapter and the HD radio tuner need to have constant power to retain memory.

The camera will still be on a switch to toggle between being powered by the constant or by the reverse lights circuit. I am going to leave constant power side of that switch on the relay so that power will be turned off when the HU is off. That way the battery won't drain down if the camera switch is left in the on position and receiving power when the ignition is off.