I have an odd issue:

So I had my boost controller solenoid wired into the ABS fuse using a fuse tap, and it turns out that this fuse is always hot. No big deal, I figured, the MS is the ground and when the car is off, the ground is inactive and there won't be a parasitic drain.

I was wrong, there is a parasitic drain and it eventually kills the battery.

What happens is that when I plug the boost controller solenoid into power, the solenoid clicks once, then I hear a clicking noise coming from the interior of the car, from what appears to be the MS. What gives? Car is off, MS should be off, what's clicking?

I have a 2002 NB with an MSPNP Pro ECU and a MAC valve. This is pretty bizarre and I'd like to get it resolved.

Also, to remedy the current situation, where can I find an ignition-switched power source in the engine bay? Do I just need to run the wire into the cabin and tap off of something there?

 

Power the boost valve from the purge solenoid valve wiring. The problem happens when you power accessories that are not powered by the same source as the ECU.