Originally Posted by
northernontario
Couple years back had a no-start issue on my '02 F150. They've got a solenoid on the firewall, and a second solenoid on the starter. The solenoid on the firewall froze... everything in the truck worked, power to everything, and when you turned the key nothing happened, not even a click.
In the process of diagnosing out in the bush (-30C, 100km away from a cell tower), I had the ignition on, and turned the heater fan on high for a minute (recommended in the manual when boosting off another vehicle, to prevent voltage spikes... not that it applied to me as I was boosting off a 2nd battery on my own). Reached back inside, turned the key, and it fired up.
The solenoid had frozen; but the connection points act as a point of resistance. Running the fan drew enough power to warm up the solenoid, as it's the solenoid that also passes power to the fuse panel for everything else in the truck... warmed up enough that it unfroze and started.