On our recent trip, I noticed that Mellow Yellow's starter had quite a
bit of hesitation when the engine was warm. Turning the key would result
in a single "chug," then a pause, then "chug, chug, chug" and the engine
would start.

This is not new, it's been going on for a couple years at least, and
it's getting worse.

Two possibilities come to mind: high resistance in the starter motor
main current path, or weak starter battery.

I am in agreement with David Beierl that fat copper cables don't "wear
out" or develop high resistances due to age. Without damage to the
insulation, the copper will be fine. The transmission's ground strap was
just re-tightened when the transmission was pulled and replaced.

Besides -- should a warm engine be easier, not harder, to turn over?

I lean toward the theory that the starter battery is getting long in the
tooth. Those things do wear out.

Unless someone talks me down, I'm just going to go out and buy a
replacement.

--
Rocky J Squirrel
'84 Westfalia: Mellow Yellow ("The Electrical Banana")
'74 Westrailia: (Ladybug Trailer company, San Juan Capistrano, Calif.)
Bend, OR
KG6RCR