When I bought my first T (about 1972) and old timer that I respected said that you should always add a 6 volt solenoid to take the wear and tear off the floor switch. So 3 cars later I did it again. I noticed that the engine didn't spin as sharply as it should, and then starting became intermittent. Crawled under today and it was hot and some of the plastic insulators were melted. Anyhow, just discarded the damn thing. This was brand new from one of the usual vendors (whom I don't fault).
This solenoid is completely not necessary.
As the saying goes- millions upon millions were made without it.
If that were the case, we'd all be using 10w-20 nondetergent oil.
I've been running a solenoid to take the load off my original starter switch for a three years now. If everything is hooked up right and grounded correctly you shouldn't have any problems. Regardless of the condition of the solenoid, I would be checking the starter for high amp draw. Those insulators won't melt under normal load.
Gave that some thought Kevin, but absolutely certain that all was wired properly and securely. The starter was just re-built professionally. The engine is relatively tight as it doesn't have lots of miles on a complete rebuild ... but starts easily by crank. The fact that the cranking is some much better with the traditional floor switch point to the same culprit. Think I will just order a new replacement floor starter switch and have it around as a back-up if ever needed. An occasional dud solenoid is I suppose a possibility. (I should add when I tapped the solenoid with a small wrench it 'locked' in the start position and I had to quickly disconnect the battery to stop it.)