[TR] Electrical Gremlin

[Randall]

> Both brake lights and fuel gauge not working.  
> 
> Power to the brake switch.

Assuming that's not a typo, it suggests the problem with the brake lights is
not one of power not getting to the switch.  Recheck using a helper to hold
the pedal down, then check the load side of the switch.  I had a lot of
switches fail, before I converted to a mechanically operated switch mounted
on the pedal box.

>  Wipers and Turn signals both 
> work, so the connections to the fuse must be okay.

The later TR3s had all separate wires to the 'green' terminals of the fuse
block, and all TR2-3 had a jumper between two terminals at the fuse block.
So, the connections could be loose/broken, or the jumper loose/broken; and
it would only affect some of the 'green circuit' items.

> So question.  While the schematic shows the circuits for the 
> fuel gauge and brake lights are separate, do they in reality 
> share a common green power line, and is that where I should 
> be seeking the open/short?

Nope, those wires join only at the fuse block.

> I could tear the wire harness apart to find out, 

Strictly a last resort.  At the very least, I would verify that there is
power in the wire (by piercing the insulation with a sharp probe) at one end
and not at the other end; before tearing into the harness.

Please note that Occam's Razor does NOT always apply ... sometimes there
really are multiple problems that just happen to occur (or get noticed) at
the same time.

Randall