73 challenger gas level gauge stopped working

[Kuruton]

Hey all, got another question for ya.
Today I installed some new spark plug wires and cleaned up some wiring in the engine bay. After which I took it for a test drive and realized I wasn't firing on one of the cylinders. Turns out the cable wasn't seated properly on the plug so I got it reseated but then noticed my gas gauge is no longer working (Sits below E). Wondering if it's possible I killed the sender/Gauge electronics with the loose spark plug cable, or if I pulled a wire loose when tidying them up with loom tape? Does the regulator/fuel sender signal interface with the bulkhead at all or anywhere in the engine bay? Thanks!

 

[Challenger RTA]

I understand what your concerns are. When welding It is advised to disconnect computer. I never fried one yet. At times when there was a ? mark in my head I would unplug it. The arc in your situation more than likely grounder to the engine. The only electronics that might get fried, would be if the an updated electronic voltage limiter in the gauge cluster. It's more than likely a fluke.
Remove drivers kick panel unplug rear body plug and test can be made from there. Also check ground strap on gas tank.

 

[moparleo]

Make sure to put some dielectric grease inside the plug and cap booths. Both seals out moisture and much easier to remove later.
Number one issue with early Mopars is Grounds. Most electrical issues can be traced back to corroded connections