general wireing question with reverse lights

[DSM's 4 life]

Ok since i got my car the reverse lights were not hooked up and when I hook the pigtails up to power there seems to be no polarity(it works both ways) this is how I was testing it


when I am only using one battery It works. but it wont work when I try to use a factory ground or the other battery

You must be logged in to view this image or video.

any help would be greatly appreciated thanks Kyle

 

[stars]

If you use the factory ground they will not work correct? May I suggest get a "test light" and check for power back to the pig tails. There is a switch on the transmission that activates and sends the current to the pig tails make sure the car is on, engine off and park brake set and put gear selector in reverse. Check for power with the test light. If you have power then all you need is a ground wire. If you have no power you have to figure that part out with a schematic and trace down the circuit from the source. If you have power then you have a ground wire issue. You know the lights do work since you tested them. Your task is to test for power and ground using a test light or multimeter, checking polarity just tells you that the circuit is functioning, you just have to figure out, is it a power source or ground source or switch problem.

Make sure your cars battery is fully charged before you do the test.

 

[DSM's 4 life]

I'm trying to wire it on a switch so I physically have to hit it for it to turn on but that won't even work I am giving it power but the ground only works off the same battery that's giveing the front power not the second one in the back.

Seriousley. Need help

 

[stars]

On your second battery in back how many ground wires do you have? You may not have a good enough ground in back for that circuit to work. Electricity flows from negative to positive, so I would add in a few more ground straps to various locations in back. You may have to run a ground wire from the front to back. Idk your setup, I'm just guessing with as little information you have given. I had my reverse lights on a switch too because I used strobe lights in place of the back up lights but I powered the circuit from my front battery. I used my back battery to power the 4 amps I had installed. I also used a battery isolator in my circuit for the two batteries. You may have to rewire the rear lights in series and install the switch. Like I mentioned I'm only guessing because idk what circuit(s) you do and do not have installed. You may just want to forget about the back battery and run a wire from the front battery thru a switch and wire it into the rear back up light circuit.