[Vwdiesel] HELP! fried starter solenoid

[Rolf Pechukas]

93 Eurovan diesel
not sure exactly what's going on
couple weeks ago I had some kind of short from ignition switch to  
starter relay in panel
wire was getting hot, meltin insulation, smoking
some guys suggested worn brushes in starter (starter was new Bosch  
rebuild 1 yr ago)
I decided to bypass ignition switch and relay - installed a manual  
starter switch from battery directly to starter solenoid
this worked great until today
now no matter what I do I can't get anything to happen at starter  
solenoid
even direct line from battery - WITH battery charger attached - gives  
nothing
starter does not even lurch or try to turn over once
I see very weak spark where wire touches solenoid contact, nothing more
is this possibly the heavy braided postive lead from battery to  
solenoid?
rainy day affect things?
any thoughts apprec
thanks
-- 

Rolf in MA