When the key is in the key on, run position (but it isn't running) the fan runs all the time, and what is the SES/CEL (Check Engine) light doing, is it on or off?
If it is off, then you need to check the wiring to the DPFE or that runs near it. It is a couple of wires off the main harness off the back of the engine near the center of the passenger side.
That MIGHT be it. Mine failed there and a few others have also had the failure. The wires had all the insulation burned off, and when they cross it behaved like this. I was crazy enough to drive mine like that, but it would always die on me in bad times, so I unwrapped the harness (these should be in braided heat resistant sheathing) and cut, added shrink wrap, soldered, and all was good.
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