Hi guys, Lately (in the past month), my car has been having a bit of struggles starting, at first it was struggling to kick over, I immediately thought my battery, which I replaced with a mates used one, temporarily fixing the problem, only to be coming back slowly. Last week I was out, I tried to start the car and it was turning over VERY slowly, waited literally 3-4 seconds, tried again, and started, wtf? Not only that, my battery voltage reading is 14.2v when running (alternator is charging), usually dropping down to 9.0v when cranking over (as normal).
Also I believe my A/C compressor is having problems, weird whistling sound when it does start and tones down fairly quickly. Also hear a similar sound when I turn the A/C on.
Tonight, prior to going out, the car started, with a LITTLE bit of struggle. Then when I tried to start it later on, NOTHING, no crank, no clicking, nothing at all. I had to clutch start it. When I got home I started diagnosing, I get reds, reading solid 12.0v on the meter, strangely enough though, only drops down to 11.2v when I go to crank it, the cat sensor light comes on, but that's also normal. Checked a few fuses, they seemed fine. Tried jump starting it, still gives me nothing. Jacked up the front end, it's on stands now, only had a very brief look-around at the starter motor, there doesn't appear to be any moisture, and all cables are plugged in. Any thoughts? I strongly believe it is something electronic, as I'd get SOME response from the starter if it was effd. Relay? Wiring? Should I start taking apart the dash and shit? Could the starter be shorted out somehow? Dust build-up? I don't know. Really appreciate the help, if you have ANY information at all, please reply!