This is weird. If the blowet is on. The starter wont work. 85 ranger, 4 cylinder 5 spd better than wife

 

Welcome to the forum

Don't have a wiring diagram for 1985 but I doubt there would be any crossover between the 2 systems, except battery voltage and grounds
Does starter work with head lights on?

And do you get a "click" with key turned to START with blower on?
Either would be a battery cable issue, corroded terminals and/or bad grounds from battery negative

If you have a volt meter test battery
12.8volts is a new battery
12.5v is a 3 year old battery
12.3v is a 5/6 year old battery

12.2v or lower is a done battery replace it