car ran fine this morning on the way to work. later on get in and turn the key and nothing at all. the start-up lights on the intrument panel flicker and are very dim. and somewhere below the dash something is making a wierd electronic buzzing / grinding noise. the fuel won't prime or anything. basically turning the key does nothing. I don't why my battery would die over a couple of hours (didn't leave my lights on). Gonna try and jumpstart to see if its the battery. But could this be a problem with the main relay or the ignition itself? Thanks in advance.

 

Could be a number of things. Maybe your alternator died and your battery drained, or perhaps your main relay went out. Sounds like your battery is weak though.

 

thanks, so would the best way to problem solve this be:
1) try jumpstart - if car starts then = dead battery, replace battery
2) if battery dies again - bad alternator (anyway to check alternator?)
3) if car still won't start - replace main relay
how do I replace / check the main relay - where is it located exactly?