Willy's Jeep / Gremlin igntion ? - carbon wires useable on old systems?

[Gremlingts@xxxx]

 A friend of mine has a '48 ( I think ) Jeep, he's had a hard time getting it 
to start. I finally asked if he had put new wires on it, when he mentioned 
the spark looked yellow, and he said the guy before him had. I asked if they 
were steel core or carbon, and he said he'd look, turned out they were 
carbon-core ( resistor) spark plug wires. I don't think a 6-volt battery and 
ignition can generate enough juice to jump thru that, anyone know different? 
It is an all original Civilian Jeep version of the M138-A ?, the pre-CJ Jeep. 
Just wanted to see if that may be his main problem. 
I also am trying to start an original '72 Gremlin with original coil, and 
it has the carbon-core wires, doesn't seem to be getting spark to the wires, 
either. I wonder if the 12,000 volt coil can handle those wires, even if it 
is 12 volts? I am getting voltage to the points finally ( had a coating of 
waxy buildup on the new points that have been sitting awhile) Thanks for 
replies, guys ( and ladies ). :D

Jerry in Virginia....( trying to start my friend's Gremlin )