05-05-2018, 04:33 PM
Out of curiosity, what Miata's have relatively weak cooling system's? I've owned at least one of every year, 90-04's, daily driven them, raced them for 15 years and never had an issue unless something was wrong in the cooling system. If the needle ever moves from where it normally lives, you have a problem.
With that in mind, going over a mountain with the AC on will not cause it to over heat, if anything having the second fan on should help. The first issue you need to figure out is what is wrong with your cooling system, then diagnose the AC staying on.
What is your coolant level with the car is cool?
Also sounds like you have a clogged heater core.
With that in mind, going over a mountain with the AC on will not cause it to over heat, if anything having the second fan on should help. The first issue you need to figure out is what is wrong with your cooling system, then diagnose the AC staying on.
What is your coolant level with the car is cool?
Also sounds like you have a clogged heater core.