Ignition start switch again?

[Ardent_Z28]

After putting a few miles on my Z28 following some upgrades and mods, I parked it and shut it off. Immediately turned the key to restart and zilch. No movement of the gauges, no power to the driver seat, no lights or headlights. I replaced the Ignition start switch just over 2 years ago but I don't recall if all the power was shut down totally back then or not. I tested the VATS plug for the reading on my key pellet and it's good, I checked the jumper on the theft deterrent relay I installed back then and it's still good. The switch is under warranty, and it is apparent I will have to deal with that part next. Can anyone enlighten me about total loss of power being normal with this issue? My battery voltage is 13.4 VDC, and I was considering installing a VATS bypass module. I have yet to test for voltage at the TDR. CPT Pro-Race build on my 4L60e, Speed Engineering's LSx stainless dual exhaust, Fastbird Performance fuel line relocation kit, Founders Performance Panhard relocation kit and adjustable panhard bar and rear LCAs and shock tower brace upgrades and now this. I am currently trying to find a new Ignition Start Switch since this one is from RockAuto dot.com AC Delco part #D1472C and is my possible source of failure. Anyone experienced this total power loss this way?

[Injuneer]

There is a fusible link at the red “+” terminal block, in the red wire that goes to pin C2 on the ignition switch (assuming wiring is still stock). Do you have 12 volts on the red wire on pin C2?

http://shbox.com/1/ignswschematic.jpg


Is it possible the rod that connects the key cylinder to the ignition switch has come loose or out of adjustmentL

[JOATMON]

^^^ What he said. I was thinking the switch just needed adjustment. The holes are slotted allowing up/down movement. BUT, when I read it again, (no headlights, no power seat), sounds like a battery cable connection either at the battery ends, the ground to the engine block or the positive terminal block on the pass fender well.

[Ardent_Z28]

Well I checked for the fusible link last night after work as suggested by @Injuneer and didn't find one. This morning I decided to check my grounds as my Momma always suggests with total power losses, and start with the battery cables as suggested by @JOATMON. It was obvious when I raised the hood...a white substance was underneath the ground stud on the passenger wheel well. It had signs of arcing due to the stud loosening after I had connected/disconnected my battery during the upgrade and mod projects since last Thanksgiving. Tightened it down and the car cranked right up. Now I can get back to the DTC 14 and 86 codes I scanned before this incident, which don't appear on my Scanmaster. Thanks for the suggestions fellas. Stay healthy and stay safe.

[Injuneer]

For future reference, are you indicating your wiring does not have these:

http://shbox.com/1/fusible.jpg

[Ardent_Z28]

Yay, I found them!!...thanks to the link you provided @Injuneer. I was mistakenly looking for a fusible link the same gauge as the battery cables (like the one on my F150). I had tucked these under a wire loom encased in a protective plastic sheath that runs to the front of the car. Now I wonder how these fusible links will look if they blow? Do they separate completely or stay intact with obvious signs of melting? It appears there is a heat shrink on them that can allow one or the other to occur when they are overloaded. Again I, as well as many others, appreciate your feedback Injuneer.

[Injuneer]

When the circuit is overloaded, the internal wire heats up and melts, opening the circuit. It may melt or deform the insulation, or it may not. So you may have to use a meter to determine if they have created an open circuit.