Pontiac Repair: d.o.a, obd ii, gas gauge

Question
todd..went to start my car and there was no power,tried to jump it and still no power,wouldn't take a boost.. noticed gas gauge was acting up when in the on position,ignition switch stuck a couple of times on that day when it went dead.. hooked up the obd II sensor and reads not supported, not reading the computer,,what could it be,, i'm thinking the ignition switch first and then possibly the computer?it's a 1998 3.1 litre grand prix, battery reads 12.6 volts..car ran fine that whole day and went to use it again and totally dead...thx for reading

Answer
Hey Rodger:

I think you on the right track. turn the ignition on and then check all the fuses for power you should have battery volatge on most of them with the key in the run position. if you have ones that are dead or are far less than that of the battery it's more than likely a switch.  but before you condem it check the connector at the base of the column. ther  are either 2 or 3 heavy geauge red wires that feed the switch battery voltage. Make sure they are powered up if not start tracking the issue back from thert to the battery. Good luck :}