Grounding the thermal switch lead on a Gen 2 won't do anything instructive because it is, well, the switch. One side of the switch sees V+ and the other side sees V+ when the switch activates, sending V+ to the fan motor, otherwise it is just a connection to ground through the fan motor. You can do as the OP did, jump the connector to see if the fan operates; I expect he did that, proving that the fuse was good.
The likelihood that the motor is bad or that the switch is bad, as compared to he didn't get it hot enough to activate the switch, is rather remote.
I STAND CORRECTED! The Generation 2 wiring is just as you say. I inadvertently overlooked Bill10's service manual extract he posted above.
I should have said, "With the ignition key ON, SHORT
) the terminals to the fan switch to activate the fan."
I was totally confused by the differences between Generation 1 and Generation 2 fan wiring:
Generation 1: Fan switch + 12 VDC lead hot at all times; fan runs when ignition turned off with sufficient lower radiator coolant temperature closing thermal switch.
Generation 2: Fan switch + 12 VDC lead hot ONLY when ignition switch ON.
Generation 1: Low-amperage control voltage flows through thermal switch, activating fan relay and consequently fan motor when lower radiator coolant temperature closes thermal switch.
Generation 2: Full fan current flows through thermal switch when ignition switch ON and thermal switch closes when lower radiator coolant temperature sufficiently high.
Generation 1: Fan fuse 10 amp; protects fan relay, associated wiring.
Generation 2: Fan fuse 15 amp; protects fan motor, associated wiring.
A thousand pardons for my error!
Still, SOMEONE must disseminate misinformation on this website, no?