So I bought an 08 WRX with 120,000 miles on it 10 months ago, and it is currently at 128,000. I came home one day from out of town and parked my car how I normally do. We had a storm that night so it got really cold and when I went out to start my car there was no crank. Charged the battery and still nothing, so I rolled it into the garage and put it on jacks. So now I start to trouble shoot, and I use my multimeter (I’m an electricians apprentice btw) and I check for continuity and the correct voltage on all my fuses and relays. But to no avail nothing was blown or not working. We checked the starter, and manually jumped it and it cranked, but I found that we weren’t getting a signal to the solenoid when we tested for continuity at the relay. Fast forward a couple days I’m taking out the center console to get to the ECU and the car battery dies. I charged it and we had 11.6 volts on it, but after flashing the lights and running the stereo the battery died and we were reading 6.4 volts. So I charged up another battery that recently died from sitting too long in my Subaru Legacy and put it in my WRX, but still it wouldn’t start. I troubleshooted again after putting in a different battery (not new) and read 12.6 volts on the battery, and I finally started reading the correct voltage on the fuses which was equal to that coming from the positive and negative terminals. After that I did an ECU reset thinking maybe the car wouldn’t start because of the immobilizer. I touched the negative and positive terminals for 30 sec. then put the car in the ON position. Btw I also bypassed the clutch safety switch thinking that would fix the problem. So now after doing all that, I’m back at square one, no crank no start. So I try to jump the clutch again by letting the car roll and letting go of the clutch in 1st gear, and it started up. As I drove it I realized it was misfiring, so I ran the AP code reader and had a misfire in cylinder 2, 3, and 4 and a PFFFE code as well. I hear the fuel pump turn on, I now hear a click at the relay when I turn the ignition to the ON position. Only thing I found was a loose ground on the starter that I assume my uncle didn’t tighten down when he pulled my clutch and flywheel. But the car had started for 2 weeks after I got it back from him with the loose ground. I don’t know what else to check for, I’ve replaced all coil packs and spark plugs, I’ve done all the clutch hydraulics and components, I just want to know if there is anything else I can do before I take it to the shop and won’t get it back for like 10 weeks again lol. Update, I’ve taken my battery to get tested, 26% life and they said it was still good.