Was told many years ago by a mechanic that if you turn off your A/C before starting your car that it would help the engine last longer. Something about the extra pull on the engine at start-up from the compressor being harder on the motor. Another mechanic later said that all I was doing was wearing out my switches. So which is it?

 

I turn everything off before turning off the car. I don't see why you need to have the AC, radio, and other stuff on before you start up.

 

so I can be cold, deaf, and well lit.

jk, but for reals, when its 105 degrees out, windows down quick and ac is needed!

 

It won't make a difference one way or the other. The A/C compressor has an electromagnetic clutch to engage/disengage it, and that clutch is disabled during engine cranking to reduce the load on the starter and battery. All cars do this to some extent. I've had cars where the radio, headlamps, vent fans, and A/C are all disabled while the engine's cranking.

Ideally, the only things powered while the engine's cranking would be the stuff that's actually necessary to start the engine (ECU, ignition coil, starter, etcetera), but depending on the car, smaller loads like dome lights, parking lights, and the radio are often still powered while the starter's engaged.

 

Yeah, I'm with Scott on this one. Definitely this stuff mattered on my 1968 Ford Galaxy. Now, not so much... I spend those neurons worrying about stuff that matters... like where my next UJ is gonna go...