No everything grounding and soldering wise is good. How do I test the alternator I'm starting to believe that's it

 

Visually looking at a solder or ground wire is not the proper method for validating whether it is good or not.

 

What is the proper way? And the battery is dying again. I am honestly clueless

 

Rotary_FD3S, have you read the FAQ? Proper grounding and alternator diagnosis is covered in it. For quick reference, I'll paraphrase both but I STRONGLY recommend you read & bookmark the Second Generation FAQ for future reference.

Charging:
When measured at the battery terminals with engine running, 13.5-15.0v is good and shows a healthy alternator. Under 13.5v means the alternator isn't charging the battery. Over 15.0v means the voltage regulator is disconnected or has failed. Shut it off NOW and replace it. Do not drive the car or you WILL fry things like your ECU.

Grounding:
You can test a ground by measuring its resistance in ohms. Put one meter lead on the ground to be tested and the other lead to an unpainted spot on the car's chassis such as the Hood Prop. A good ground will read 0.07 ohms, but up to 0.10 ohms is what I consider good. If it reads above 0.10, clean it per Aaron Cake's Ground FAQ (linked to in the FAQ) untill you see BARE SHINY METAL.

As for your varying voltage (due to output curve) and testing for parasitic draw, Satch is correct though you can do so with the meter in-line on either battery terminal. I do it on the positive terminal in order to isolate circuits easier. At the same time, it is well known the that FC Alternators (70A for S4, 80A for S5) are overworked from the factory. Most swap to a 100 amp FD alternator using the #11480 pulley available from Mazdatrix. I'm using an alternator from a 3.8L Ford Taurus (92-95 model) and it puts out 130 Amps. As soon as I start the engine, it perks right up to 14.1-14.2v. Even under full load from the lights, defroster, heat & power windows, it never drops below 13.5v.

Wiring is the same as the S5/FD Alts, one key-switched 12v and one battery 12v, but it does need some simple flat adapter brackets for install. You'll need the aforementioned pulley from Mazdatrix too. Be sure to upgrade the output cable to at least 4awg with any alternator upgrade. Technically, there are 3 cables on the positive battery terminal. One to starter (4awg), one to underhood fuse panel (8awg) and one to alternator (8awg), but that last one is spliced into the fuse panel cable. If you're going to do an upgrade, I think it would be a wise idea to de-loom and remove the old alternator output cable to prevent accidental shorts. As there would be three lugs on the positive terminal, spending $4 on a pair of Marine Battery terminals, the kind with the wing nuts on them, would be a very smart idea too.

Taurus Alt + 4Awg Cable + Marine Terminals = No more dead battery

The above electrical work and replacing the battery to starter cables with fresh ones (48" for positive starter cable, 24" for both segments of the ground cable), cleaning up the main underhood ground in the process, can and will work miracles on your car. I used 4awg cable and lugs from a welding supply store (DeLille Oxygen). Cable was ~$1/foot and the lugs roughly 50 cents each. Just follow Aaron Cake's directions to the letter for soldering them and they'll be infinitely better than the chinese crap from the parts store.

 

OK I'll read the FAQ. Thank you very much I really hope this helps

 

It was the battery... gah I feel stupid hahaha. But that didn't fix the problem where the clock and radio only work when I press the brake. And also the door ajar light is always on when my foot is off the brake. And the e-brake light randomly comes on. Thats probably grounds I'm assuming?