well first off a fan that has no voltage to it will not catch fire unless set on fire. this shop you have it sounds a little off. checked wires for ohms is ok to check for open i circuits but depending on gauge of wire and how long it is will have diffrent ohms readings. i hope they checked wire harnes with everything unhooked from that circuit. some sensors can be damaged by checking that way. is the timing correct? if it off by one tooth can lead to alot of running problems and set alot of codes. what codes is it setting right now?