jump radiator fan switch, a/c fan comes on..?

91 ls, cooling fan doesnt come on, overheats, been parked for months, second car, just need to sell it.

fuses good, relays good, fans good, so whats left? … the fan switch

crawl under there and jump the switch next to the oil filter and the a/c fan comes on… wtf?

this suppose to happen?

i searched, didnt find anything like this…

i know the cooling fan from the a/c fan

isnt that a little weird?