Wife went to start car few days ago to run errands and the second she turned the key to start, there was a sound never made before and now there is a substantial power drain on the electrical system.
I've literally tested every fuse and every relay. I've disconnected both the alternator and starter and still when the key is in the on position, the system struggles to keep power.
Car uses uses basic keys, not the keyless fobs. If I remove the EGI relay or just remove the engine 20A fuse, the power loss is solved, but I lose a crap ton of components when doing so, so not much of a test.
The odd deal is it appears the throttle valve and IAC pull most of this power, so much that whichever component is the source of the 'electrical whine' sound the car has always made will not come online until the power recovers. There are times when I turn the key to on and the instrument cluster flashes, interior lights are very dim, etc...the intake components cycle and then the whine noise starts and all is well. At this point if I turn on the headlamps, push the brake pedal, or try to start the engine all hell breaks loose and the power drops. My meter will go from 12.8 to as low as 5.# volts.
My gut says the key switch is screwed, but I haven't tested it and it basically works as designed for Acc and On power distribution...
Anyone know all of the components on the 20A engine fuse leg that can rob that much power when the key is in the on position but not blow the fuse?

 

Get your battery professionally tested.