[Vwdiesel] no start, relay and a smoke puff

[Chris Jude]

Folks,

For the last couple weeks I've bee having an occasional no start situation
with the 85 Jetta.  It's not every time, but occasionally the car wont
start, and sometimes it won't start and there will be a small puff of smoke
from the fuse box area.  I've noticed that the insulation of the Brown wire
going to the throttle position sensor switch is melted.  When I remove the
glow plug relay the car will crank and start fine (sans glow plugs).
Last week, after this happened a couple days in a row, the battery died.  I
tightened up a wire going to the alternator and that seemed to fix that
problem, and the car started regularly for several days, no problems.
Today the problem came back, with some smoke, I haven't looked yet to see
if there is another fried wire.
Any thoughts on where to look?  I don't see any bad connections at the fuse
box, and the glow plug relay pins look fine.  The battery is charging as
well.

Thanks,
Chris
1985 VW Jetta NA
Pittsboro, NC