Hey Bill, just wanted to add another possible remedy to your two. My radiator fins were extremely clogged with dirt/sand/leaves, etc and I attribute much of my standstill/idling overheating problems to that. Tha fan is spinning to slow at idle to suck enough air in through the radiator to properly cool the engine bay. My clutch was fine. I also think that the auxiliary fan, if all other normal cooling system components are working well, should not have to kick in.....I know you know way more about these things than I do, but those are my observations, and I'm sure there is validity to them.