Appreciate the input. The switch on the ground strap will be accessible by the battery box and only for convenience when working on the car vs reaching down to the wheel well and flipping the pos switch. I know...first world problems.
Can you elaborate on the H/D diode that we can splice into the alt wire? Maybe a link to one so I can see what you're talking about? I can follow instructions and pictures very well...but I just don't have the experience to know what some of these parts are. Thank you!!
I'll need to dig into my resources here.
I was given a couple of
"Stud Blocking Diodes" from an electrical engineer friend that played around with H/D electric motors.[they are not cheap at approx $10-$12 vs about 10c each]
It worked really well [especially on my old B/B Corvette race car where shorting out tools was an occupational hazzard]
Another method is to use a DPST switch to switch off both the Alt wire and Ignition circuit at the same time.
But ^^^ I am not fond of disconnecting the Alt Charge Wire while the Alt is still charging [throwing the switch with the engine running]
Having the Alt Charge Wire connected to the battery acts like a buffer when the engine is still winding down to a halt.
Is your car a track car or street car.
Mustangs are easy to wire in a Isolator switch [the old conventional method]
1:Mount the switch in the Aerial Hole on the passenger side fender. next to where the old battery was mounted
2:Crimp an eye to the old battery + cable and bolt it "downstream" on this Isolator switch
3:Crimp an eye to the old main power feed and also bolt it "downstream" on this Isolator switch
4:Make up a new cable to go to the battery box in the rear and connect this "Upstream" side of the Isolator switch
5:Connect the alternator charge wire [that normally goes to battery] to the "Upstream" side of the Isolator switch.
You could probably locate and splice this wire into the main fusebox and fusible link.
If you use the marine style battery isolator switch on the fender /base of the windshield [below]
Clock/Rotate the switch in a position so the Flag/Key is
Trailing in the on position and East/West in the off position.
Approx 35 years ago I learnt a "pants shitting lesson" when me and a friend were practicing in a Rally car on back country gravel roads at night.[I was the passenger]
We came sliding around a corner [reasonably fast] when suddenly every thing went "black" and we rolled down a bank.
What happened was some branches on the roadside brushed the isolator switch and flipped it into off position.
Everything went dead. Ever since then I've clocked/mounted the switch so this cannot happen.