Over Voltage with New Battery Disconnect Switch

gradedcatfood said

Little update. I think I have found the best way forward for my situation. I plan on "breaking" the red and black wire that runs in series with the amp meter under the dash. I have already deleted that gauge and they are currently connected together via a nut/bolt.

With how I wried my ignition box and fuel pump relay switch when I disconnect those two wires the car shuts off. So my plan is to run a 10ga wire from the red wire to the master disconnect, then run another wire from the other side of the master disconnect back to the black wire which should take care of all this.

I know it wont shut the entire power off to the car but I believe this will meet NHRA rules as the car and fuel will shut off with 1 push of the switch (accessed from outside the car of course)

Thank you again for all your help

Click to expand...

I don't think you want to do that. Do you remember the "old wives tale" about "testing" alternators? The "old wives tale" says if you disconnect the battery cable and the engine keeps running, the alternator is good. If the engine quits the alternator is bad

There's a couple or more things wrong with this:

1....If you do this "test" and the alternator is running slow, it might not be charging enough to run the engine, and may die, falsely telling you "it is bad."

2...If you do this test and the alternator only partially works (couple or 3 bad diodes.........) it may output enough to run the engine and little else, giving you the false notion "it is good."

3....UNHOOKING and alternator under load causes a HIGH VOLTAGE SPIKE and can be hard on electronics in the car.

ALSO

Having some sort of disconnect that leaves some wiring "hot" I BELIEVE (my opinion) does NOT meet the spirit or intent of the rules. But it's your neck.