During my routine spark plug and TW-timer cleaning I noticed some high voltage arcing inside(through) the firewall adjacent to #1 coil box insulator. I was testing the timer circuit after cleaning the timer to verify coil buzz in firing sequence. This was done with none of the high tension wires hooked up to a plug or near a ground. I know that electricity will take the least resistance path to ground, but should I be concerned about the fact that when no ground is provided #1 coil arcs to the firewall, or is this normal? Perhaps I need a new coil box rebuild?
Possibly, but you should never let a coil buzz without the plug connected. It can damage your coil.
Yup, Its time to install a new Fun Projects coil box kit. Takes about 20 minutes.
For me a rebuilt coil box is as important as buying a new radiator or at the very least having a radiator recored.
If you intend to drive and enjoy your T a good coil box is a must.
Probably about 20 years ago I had a coil box starting to arc on one of the coils. Getting caught in a rain and having the wood get wet can cause the arcing and it can cause carbon tracking and after that replacement is necessary.
I bought several sizes of plexi glass and cut my own using the wood as my pattern. Good winter project. You could call it my "Fun Project" and as I said that was about 20 years ago and I have no problems with it.
I had intermittent arcing through the wood of my '15.... whenever the car got wet (as in washed) it started to run rough. I realized what was happening when I got shocked by it.
I installed the rebuild kit that Fun Projects sells. It can't be for quality, is not visible once installed, lines the box up correctly so the coils fit right and is a permanent, foolproof fix.
It might be OK after you install the wires, but carbon itself is a conductor, so you could very well lose spark until you re-wood the coil box.