Where to get accessory power in the trunk?

[switlikbob]

I plan on wiring up an amp in the trunk, and I was wondering where to grab some accessory power? It this point, as I have the car stripped (I just ran the battery relocation cable), I could even grab the wire from another source and run it to the trunk.

TIA, BOB

[milotrain]

If you've relocated the battery to the trunk I'd run power directly from the battery to the amp in as short a run as you can. The amp should have switching control and hopefully no parasitic draw when off. Wire that switching control to the dash.

[switlikbob]

I think what you are calling "switching control" I am calling "accessory power". I have also heard it called "ignition power". There is a loom of wires near the driver's side tail lights. I would imagine that one of those wires is for that purpose. If I do wire it to the dash, which wire?

[Tom D]

my 77 has only one accessory wire in the trunk.
it is consent hot, located at the left lid hinge, next to the shock mount.
it's for powering the optional trunk light and certainly not heavy enough for anything but to switch a relay for the amp.

[milotrain]

o_O

Ok so you have an amp. It needs power, that's going to come off the battery through a large wire that should be fused for just above what the amp will draw. However you don't want the amp on all the time, so the amp has "switching power" which could eaisly be called "accessory" power. All this feed does is tell the amp when to turn on and when to turn off, so that it doesn't run while the car is off. You could connect that feed to any +12v in the car that is on when the car is on. I don't know if there is a wire like this in the trunk. If you connected it to say the running lights then the amp would come on when you turn the lights on.

But basically all you need to do is send 12v to the accessory/switching feed on the amp. You could do this many ways.

1. connect it to the ignition accessory. (look for a thread on push button start it will have all the pinouts of the ignition tumbler) [problem here is that the amp is on when the car is on regardless of whether the head unit is on]

2. connect it to a switch and that switch to the ignition accessory. [now you have to turn the amp on with the switch but it's off when you don't want it on]

3. wire it to the head units "accessory" wire or some other +12v out line on the head unit. [almost all head units have a +12v in and a +12v out. The out is for things like switching an external amp or switching an electric power antenna. You'll need to find the pinout of your headunit to insure that it has this feature]

[dhlthr]

o_O



3. wire it to the head units "accessory" wire or some other +12v out line on the head unit. [almost all head units have a +12v in and a +12v out. The out is for things like switching an external amp or switching an electric power antenna. You'll need to find the pinout of your headunit to insure that it has this feature]

All aftermarket headunits that I have ever seen will have a blue wire (industry standard) usually labeled power antenna accessory. This will switch your amp on, but as told before you will need to run a constant hot from the battery. Depending on size of the amp and how far you have to run you cable will relate to size of cable needed.

[bmac320i]

o_O

Ok so you have an amp. It needs power, that's going to come off the battery through a large wire that should be fused for just above what the amp will draw. However you don't want the amp on all the time, so the amp has "switching power" which could eaisly be called "accessory" power. All this feed does is tell the amp when to turn on and when to turn off, so that it doesn't run while the car is off. You could connect that feed to any +12v in the car that is on when the car is on. I don't know if there is a wire like this in the trunk. If you connected it to say the running lights then the amp would come on when you turn the lights on.

But basically all you need to do is send 12v to the accessory/switching feed on the amp. You could do this many ways.

1. connect it to the ignition accessory. (look for a thread on push button start it will have all the pinouts of the ignition tumbler) [problem here is that the amp is on when the car is on regardless of whether the head unit is on]

2. connect it to a switch and that switch to the ignition accessory. [now you have to turn the amp on with the switch but it's off when you don't want it on]

3. wire it to the head units "accessory" wire or some other +12v out line on the head unit. [almost all head units have a +12v in and a +12v out. The out is for things like switching an external amp or switching an electric power antenna. You'll need to find the pinout of your headunit to insure that it has this feature]

Im doing #3

[switlikbob]

Thanks for all of the help guys. I think I will also do #3. I totally forgot about the switched power output on the head unit (I've wired a few amps in my time).