1988 8v n/a auto. Oh wise ones, have searched forums and exact simple solution has not been located and here's the issue: Upon turning the ignition key, before starting engine with fuelpump priming, the USA driverside cooling fan turns on, and runs continuosly, and turns off and stays off when engine shut off. No A/C--was not working when acquired. New radiator last year, along with thermostat, matching thermoswitch temp and has worked correctly until I replaced battery, new correct NGK plugs, cap, rotor, and I replaced the O2 Sensor....all without dislodging ANY other wires, and have already checked grounds and fusebox. I may very well be answering my own question but does this simply sound like a stuck thermoswitch or is there a relay I need to be looking for as well? I DO own a Bentley, but even though I have never had any overheating issues and especially now, with the fan running all the time, would like to make sure the engine is running at correct temp and cycling on and off. Note: This does not matter if it is first thing in the morning or after being driven, it consistantly comes on at the accessory point of key turn and stays on with engine running. Also, why/what changing the O2 sensor (correct bosch--no splicing) and new battery cause this? Thanks and sorry for the simplicity of this question but no ? is dumb, right? Thanks in advance. I will post pics this Summer.