Compressor Sticky Contactor

A new air compressor has found its way into my garage. I've wired it up according to the diagram. It scared the crap out of me when I turned on the breaker, since the switch on the compressor was off.

Today, after draining the tank, I turned off the breaker. What I found was that if I moved the switch from OFF to ON, the contactor closed as expected. But if the switch was turned OFF, the contactor did not OPEN. If the mechanism was fiddled with, then it would OPEN. However it would not ever OPEN properly when going from ON to OFF without manual intervention. This intervention can't happen with the electrical box cover on.

One extra fact - the temperature in the garage this morning was 42F.

Got any advice on how to fix this? I'm guessing better lubricant on the mechanism, or fiddling with the spring. I'm reluctant to change the spring tension - since I want it to work in the summer.

What say the collective?

I vote "fiddle with spring".

That or just use the circuit breaker like a switch. It's not that I'm really lazy or anything. Its just that, like electricity, I too like to take the path of least resistance.

If it's brand new get replacement contactor. New to you... spray with this, lube if necessary

It is new. I have contacted the company (about their contactors ).

Wish I knew where the critical lube points were. Kind of cramped - and dark back there, so it is hard to find the binding pivot points. I don't want to randomly oil everything. Something about lots of oil, sparking contactors running at 220V and 30A bothers me.