Thread: Relay Question

Originally Posted by mdawg

I plan to get a vary bare setup running in my car tomorrow with no dash or anything just to get an idea how I will finally run everything. The question I have is, will it be fine to use the existing 4gauge wire running to my amp and split it into a relay that will go to my inverter? Another question is, the relay I have is going to be very hard to fit a 4gauge wire on the end, are they all like this? Now to my final question I think I am going to just tap into my radio harness for the ACC wire to trip the relay, since this is such a small wire can I run a very small wire for that through my car to the trunk (I have a good amount of 22gauge)? Any input is appreciated thanks!

My setup has a 4 gauge wire running from the front to the back. In the middle of the 4 gauge wire is a circuit breaker and a splitter that has a 8 gauge wire for the PC. All though this is a laptop i assume, i would avoid using a inverter, they are not very reliable. If you still decided to use the inverter, I think the way it works, is you have the 12v (4 gauge) to the inverter 12v then the other to ground. Then the inverter should also have a remote wire which would go to the radio harness ACC wire. If it doesnt have a remote wire, then you would use the relay........

acc would go to one side, then the other to the ground.
then 12 V to one side and other side of relay to inverter.

Code:

                                             12V
                                    ---------------
                                    -        O    -
                                    -             -
                       ACC----------- O         O ------------ TO GROUND
                                    -             -
                                    -        O    -
                                    ---------------
                                             Inverter

If you are wondering how to connect the 4 gauge to the relay, i would use a distrobution block.

just a FYI.
the circuit breaker should be as close to the battery as possible (eg less than a foot away)
that way more of your wire is protected if something should chop into it somewhere

im in the process of making a crude power controller for my car

i have a 555 chip and a relay to open the 1st relay for a 5 min window
this is triggered off the car alarm door pulse.
in that 5 mins i can start the pc up by pushing its power button.
after that 5 mins the relay will close and, no power to the pc

to keep the car pc running...
the pc is always connected to permanent power, not ACC.
I'm using a 2nd relay which is triggered from the 12V line off the PSU in the pc.

this way you can turn the car off and the pc stays running.
when you shut the pc down, 12v stops, relay opens and pc has 0 power.

or uber basic option, put a switch in the power line to the pc and just flick it on and off when you want