Ghost in the machine

[jmjp5055]

Good morning People

something weird going on with my vert ,after sitting for 24 hours I go to start it,  it clicks , it clicks then starts, have new battery,  new starter both replaced when this  began.when I bring it in ,hasn’t happened for the mechanic yet.  Alternator tested , it’s working 13 volt output but dash guage says different 11 to 12 volt , battery no sign of it being dead or low , car starts, 
heavy draw when power windows or air conditioning used. 
problem #2 air conditioner compressor would not kick on even when directly jumped by mechanic so I’m out for a Sunday drive I put air conditioning on and wala the compressor kicks on an hour or so then quits, Freon checked BTW, full. 
So I go to drop car off for compressor replacement , starting problem, no click, turned key at least 3 times, finally turned key held and it took a moment but started. and the air conditioning works again, my mechanic baffled, me baffled. Hope I explained this clearly any suggestions, anyone experienced this?

Thanks for any leads

 

Edited June 8, 2020 by jmjp5055
Needed to add the starting symptom

[Pontiac6KSTEAWD]

Sounds like a fusible link to me. I cant remember where they are on these cars. Its either that, or the alternator is going south slowly.

[oldmangrimes]

Maybe a grounding problem?   I had a similar no-start problem not with a w-body, with my Dodge Durango.  ( I don't think it had anything to do with the A/C but I may not have checked the A/C).   Anyway, I was able to get it started by jump-starting itself, meaning that I ran a jumper cable from my battery negative post to the engine block and the car started just fine.   I found that I had a corroded terminal on the engine ground cable at the engine, I cleaned it and it's been fine for a couple years.    The voltages measured at the battery, alternator showed ok, but if there is very much resistance somewhere in the circuit, the voltage that the device (A/C compressor, car computers, dash gauges, or something else) sees under a surge load (car start, A/C compressor start, etc.) will be low and will cause it to malfunction.   

Maybe try running a jumper cable to check if the engine block is grounded, or if some other ground is bad.   Maybe clean some connections to the suspect component (A/C Compressor).   

[55trucker]

Not surprised that the *mech* couldn't figure this one out.....

 

possible ign switch failure.......Not the tumbler assembly, but the switch itself, what you're describing is a classic example of worn contacts failing to make when the key is turned.