I will start with an apology for a long winded post regarding 1st an electrical nightmare and second a bizarre brake problem:
Electrical: A couple months ago my left turn signal stopped flashing, had to manually move the lever, but still lit so I just dealt with it. Then at the beginning of April, my running lights went out entirely; no tail, parking, side markers or turn signals. I checked the fuses & replaced the fuse that was blown with an identical fuse, 25a (markings are gone on the box so I had no idea what was needed, but should've been 10a!) Well everything came back on except that pesky left turn problem. Well, after 40 miles of driving as dusk approached, I turned on the lights and 10 minutes later the cab filled with smoke!! Well, I pulled over & killed the engine & lights, then looked under the dash at the fuse box and the park lamp fuse was melted! Now I drove the rest of the way minus lights and the next day drove home. Fast forward a month of driving only in daylight as I have had no time to work on it at night being a single father, but I finally had an opportunity to begin a thorough inspection last week and I found a wire in the wiring harness behind the grill that was completely burned through, no insulation left at all which of course melted several others. I followed it from there into the engine compartment along the driver's side inner fender to a grey plug, burned the entire way. It was also burned on the other side of the plug and melted to other wires all the way to the pass through connection on the firewall. I then went under the dash, cut away the electrical tape from the wiring harnesses and found more melted wiring. One was blue & went to the headlight switch where it connected with another blue wire at the "R" connection on the switch. 1 of the blue lines went up into the dash behind the cluster, the other was so far gone that it broke while tracing it down, BUT there was also another completely toasted line which I determined to be red with a blue tracer from the melted insulation stuck to the other wiring in the harness, it went to the fuse box for the park lmp fuse. This came from connection "B2" on the switch & also had a twin red w/blue tracer in that connector that went up into the dash. The orange w/black tracer from "I" to the inst. lamp fuse was burned as well (these were ALL 18ga wires), the red 12ga line to "B1" from the splice was burned as well. I replaced all burned 18 ga lines with 14ga wire & 10ga to the "B2" connection and the rest to where the existing lines were intact and soldered them together & used heat shrink on the connections. I replaced the head light switch from a newer model bone yard find that had 3 extra connections (U,P & B3) but the rest were identical so I see no issue with it though I did order a new switch from rock auto prior to the BY trip. Anyway, I now have both signals front & rear flashing, but my headlights have no power and my running lights keep blowing the fuse, even if I throw that 25a fuse in there. Will I need to start from scratch & replace the lines from the switch to the front lights and again all the way to the rear lighting plus up into the dash as well? should I use the 18ga where it was? I was planning on the headlight upgrade so I have no issue doing that now but that rats nest under the dash is a nightmare!!! There have gotta be 50 black lines, 25 orange w/tracer, 10 whites blues etc...plus there is a relay that the wiring was burned up on under the left dash or kick panel as well, but I can't find it on any wiring diagram/schematic anywhere!!! I do not have fog lights...so its not for them. Brakes: This is weird. My brakes work fine 99% of the time, but when I parallel park or cut my wheels hard in any direction, 3 point turns, etc. I lose 90% of my braking. The pedal will go flat to the floor! A terrifying experience the first couple of times...but now that I expect it, I pump my brakes and they work fine again. I have no leaks in my system, no fluid loss and no vacuum leak. I replaced the check valve on the booster to no avail. I ordered a new booster and master cylinder yesterday, but if that isn't it, what can it be? Has this ever happened to anyone or have you heard of it?? As I said, only happens if I turn wheels to the stop or 3 point turns, never going straight or making regular turns at intersections.

I'm at my wit's end here & appreciate any help, thanks!