[Mrmalibuman]

I just bought an 09 Malibu. I’ve used a test light to test the starter by touching the casing and with the positive leader from the test light connected to the battery positive, it read it had power. When I hooked up the negative leader to the negative on the battery, I got nothing. I went ahead and tested the 30 amp fuse in the engine bay for power. One side of the prongs lit up, other side didn’t. (Not sure if that’s means anything) I then pulled the starter wire (purple) out of the starter and attempted to start the car and got no power to the test light. (Not the best connection but was in) I’m thinking it is the ignition switch but I’m looking for second opinions. Thanks in advance.

 

[DrivenDaily]

The car has 3 separate Engine, Transmission, and Body Control Modules.

I would wager that it won't be the key. All the key switch does is send a signal to the BCM that says "I want to start the engine." The BCM checks for various things, then sends a signal to the ECM and the starter relay.

That 30A fuse that's hot on 1 side and not on the other is your first clue that it's either a bad fuse or a damaged terminal in the fuse socket. In general, if any fuse is hot on one side, it'll be hot on both sides.

If you replace the 30A fuse and it pops again, there's something wrong in the wiring or at the starter, such as the solenoid.

You didn't tell us which engine it has.