Starting Issues

1995 Chevrolet Truck, 210,000 miles, original owner. Has a delay when starting. No warnings in dash. I will turn the key into the cranking position and nothing happens and then holding the key in the cranking position 1-2 seconds later it starts up. This has happend before (about 1 year ago-just would not start up, tried rocking it, kicking it, etc. Dash and lights came on) and it was towed in and the mechanic changed the key ignition wiring harness and it worked, but I am running into the same problem.(Another ignition wiring harness?) Another thing that is happening is when I put on the turn signal, my battery guage moves with the signal flashing-it drops about 1-2 marks. Up, down, up, down. Also, In the mornings, when I turn the key to the start position, I hear a noise(low wining noise) for about 4 seconds and then a click. The starting problem happens all the time not a certain part of the day(temp). I just put in a new battery 2 weeks ago, alternator was changed about 1-2 years ago(Autozone-lifetime warranty), Spark plugs changed about 2 weeks ago-looked like normal wear. Have not checked fuses but I figure if a fuse blows, it just won't work. I have never changed the starter or selinoid but the last time I had this problem I took the alternater, starter & seliinoid up to autozone and they stated it checked out fine. They checked the test codes when I was there last year and it came up an ERG valve (fuel/air mixture) and it was changed but it did not help. When it does start it runs great-no problems. It did have a little hesitation when stopped at a light, stop sign but a fuel cleaner pretty much ironed that out. I really appreciate your help.