Hyundai Repair: Hyundai CPS, crankshaft position sensor, hyundai sante fe

Question
I have a Hyundai Sante Fe SUV 2002 2.7 V-6 engine and I just replaced the cps (crankshaft position sensor) last week, suv started up just fine ran great all week even had more power than it did since I bought it 5 years ago, until it got all muggy and humid and started raining. Now I'm having problems getting it started it is identical to before I replaced the cps, won't start won't even turn over just makes the same hollow electrical humming sound when I turn the key..... could it possibly be the cps again or is there a short in the system somewhere causing a miss fire?? Any help would be great, Thanks!

Answer
If the engine isn't cranking, there are three basic possibilities:
1. Not enough voltage reaching starter (for any reason) to crank the engine.
2. Problem with starter.
3. Engine too hard to turn (i.e. mechanical issue with engine or drive accessory).  

The first place to start is with the battery.  If you have one, attach a digital voltmeter across the battery terminals and read the voltage while attempting to crank the engine.  If the voltage drops below 9V, the battery is discharged and will need to be charged or replaced.