I have a 1988 Chevy K5 Blazer. I let it sit for about 5 years. I recently attempted to start it up to move it off my RV pad but when I put my Key in don't get anything. I replaced the battery and now I get my seatbelt light but no check engine light. Everything I have found says that it's either your starter or your check engine bulb is burned out. So I replaced the starter. I still get no check engine light and it won't still won't attempt to crank. However now I am hearing a hum which I'm pretty sure is my fuel pump. I have checked all the internal fuses and they seem fine. I would imagine my alternator is dead at this point in time could that be causing the problem I am experiencing or could it be something else? I have read it might be my ECM but most people state it's very rare for one of those to go out.