Couple of weeks ago I noticed my belts were getting old so I got some replacements; the power steering pump belt was too big, so I put the old one back on, left the new alt. belt on, and noticed I had some voltage problems; I had pulled the wires off of the alt. and put them back on in order to tighten up the power steer belt... since then, I have replaced my alt, the wires going into the alt, the battery, re did the grounds going to the engine, alt, and firewall, checking voltage goes like this.... volt is find until I hit the brakes, then the needle jumps, same when I use the turn signal, the needle jumps, if the lights are on, wipers on, car in drive, brakes on, and maybe a turn signal, my voltage is jumping from about 10 to 13, if it is in park, it jumps from about 13 to 14... i have bought a new wire harness for the engine, hadn't gotten it yet, so far I have spent over $300 on new parts that I did not need... it is not the gauge, it is not anything that I have already checked, replaced or tested...... any ideas? neutral safety switch?? Ignition switch?? Ignition coil?? Starter and solenoid is newish, bought about a year ago..