12vdc pilot light won't light

I was wondering if you could help me out with a small situation I have created while upgrading the stereo system in my RV?While changing out the tuner I installed a SPDT switch in the dash with a standard 12vdc automotive type pilot light next to it. My intentions where to supply ignition switched 12vdc to one lug of the switch and constant 12vdc from the house battery to the other .. taking the supply voltage for the tuner off the center lug.The 1/2" hole  next to the switch (in the dashboard) is to house the pilot light which was to indicate power being drawn from the house battery when switched to that position.Well, I wired the pilot light in series with the 12vdc from the house battery .. the other leg to the switch .. when in the house battery position the light would not light but the tuner would function as the light would pass current.I called Crutchfield (my stereo component supplier) and ran the situation by them .. after some head scratching on their part it was decided that the tuner is only drawing milliamps to switch it on and that there wasn't enough current flow through the bulb to allow it to glow. I now have this beautiful 1/2" hole in my dash and I really would like to be able to have a pilot light on to indicate draw off of the house battery .. there must be a way to create some current flow through that bulb, I'm just a little rustier than I thought. Any ideas or would you know of an electronics 101 site I could pose the same question?Thanks in advance.johnnybgood

Replace the SPDT with a DPDT. Connect the battery to one contact on the end and the tuner to the center contact on the same pole. Connect the house side to both poles on the other end of the switch. One side of the pilot light get connected to the other center contact and the other side of the pilot light gets grounded. I hope I didnt't confuse you, but its one of those simple things thats hard to explain.

Are you trying to have the light come on when the switch is switched to the on position? if yes, the you need to wire the light in parallel with the head unit. wire the battery to the common of the switch. Wire the head unit and one wire of the light to the Normally open leg of the switch. Wire the other wire of the light to ground. When the switch is turned on, both the head unit and the light will turn on, when the switch is turned off, both light and head unit will turn off. Good luck, Tom