how hot should plug wires be?
 

1990 sl, tried rerouting plug wire to see if crossed wires was cause of rough running, and after driving for ten minutes, plug wires were too hot to touch, is this normal?

They shouldn't be any hotter than the rest of the engine compartment near the wires. Heat comes from current, not voltage, and there's hardly any current flowing in spark plug wires.

If you're concerned about crossfire, try looking at night with all the lights out. Or do the superman test, run your tongue along the wires with the engine running. :eek:

thanks for the info
 

I will pass on the superman test, thank you.