Grounding through throttle cable, Return spring burned the crap outta me! - SOLVED Options

[clapeza]

Got the FI back in my car (1970 1.7L) and working recently. The PO had cut the throttle cable for the carb conversion, so I installed a new TerryCable.
I noticed that the throttle cable got hot. I figured that the ground strap was corroded or broken (I can see it, but can't get to it now.)

I installed a new ground from the rearmost engine case bolt to the battery ground stud on the passenger side of the engine compartment. I used a generic 4 ga battery ground cable from my FLAPS. One end is on top of the battery ground cable. The other is on the bolt that holds the oil bath air cleaner "shelf". This end of the cable is sandwiched between 2 washers on top of the shelf arm that the bolt goes through, with the nut holding it all down tight.

I cranked the car and it ran easily, and the throttle cable was no longer hot, or even warm. Success? Not so fast...

I then replaced the bushings in the accelerator pedal bracket, so it's nice and smooth now.

Didn't get a chance to crank it because I ran out of time that day.

I cranked it today, and blipped the throttle by hand on the throttle body. I thought I saw a tiny spark at the throttle return spring where it attaches to the rear wall. I touched the spring lightly with my finger and burned the crap out of it! The engine had been running only about 10 seconds at this point.

What gives?

Theory: The new accelerator pedal bushings improved the electrical connection to the body. The new grounding cable isn't making good enough contact to the engine case, so the engine is still preferring to ground through the throttle cable.

Assumption: A 4ga cable connected from the engine case straight to the body where the battery connects is an equal (if not superior) ground compared to the transmission ground strap.

I still plan on inspecting and possibly replacing the transmission ground strap, but I'm curious as to why I burned my finger...

Ideas? Advice?

[clapeza]

I got a ground cable exactly like the one in Spoke's previous post and connected one end to the alternator mounting bolt, the one shown in the alternator replacement tutorial (http://www.914world.com/bbs2/uploads/post-419-1197334371.jpg).
The other end is connected to the engine case through a bolt near the taco plate. My previous extra ground cable from the engine case has been disconnected.
As previously said, a new ground strap has been run from the stud under the trunk to the transmission. I couldn't get a wrench on the original ground strap bolt, but I did attach it to a bolt on the transmission case nearby.

With the car on, but not running, I read 0.2v from the spring to the chassis. Car running, it read 8.4v, and got hot again. I did also see that my alternator has been replaced with a remanufactured one at some point in the past, so that opens up a whole can of worms of possibilities.

The engine and the transmission have not been painted.

I'll try to get pics of the spring and throttle body, and to check the voltage at the battery when running. I did that sometime before I got the new throttle cable hooked up, and was seeing about 13.6v while running.

I need to check my alternator gauge bulb. I know the battery shouldn't charge if it's blown, but it seemed to be charging before.