2002 Blazer Battery/Oil Pressure Sensor Connection?
 

I have a 2002 Chevy Blazer, V6, roughly 76,000 miles. For about 5 months now, I have noticed when my truck is in idle, the oil pressure sensor JUMPS up and down, but not all the way to the high/low extremes (sometimes very quickly and sharp, other times more slowly - it really depends on how long you have been driving). The truck also runs pretty rough while sitting in idle. Along the same lines, whether the truck is idle or in motion, the dome and dash lights flicker - all the time. Over these past 5 months, these problems have been getting worse. However, just last night my 'Service Engine Soon' light went on. Do you think there is a connection between the battery and the oil sensor? I am always up to date on oil changes and check the oil level constantly. Other than when in idle, the truck runs fine.

RE: 2002 Blazer Battery/Oil Pressure Sensor Connection?
 

Some oil sensors in these trucks like to be more finicky than others. So long as your oil pressure isn't dropping down below 10psi on the gauge, you should be fine.

On the CEL, I would go down to Autozone, Advanced Auto, etc and have the codes read. Post back up here with the codes and we'll do our best to help you diagnose and repair the problem.

RE: 2002 Blazer Battery/Oil Pressure Sensor Connection?
 

Turns out the codes the the engine light was for a defective coolant thermostat. So, that rules out any possiblies with it being connected to the actual problems.

I did get some other advise, but I was hoping to see if you could come up with anything else that you might think it could be.

The only other thing I forgot to mention was that when I turn on my heat (not the air, but ONLY the heat), I'm not sure if it's because of the fan power or just that the heat in general is on but it seems that my battery power seems to deminish quite a bit. Once heat is off, the car goes back to behaving normally (well...behaving normally for my car...lights flickering, car running rough in idle, oil pressure gauge jumping at idle).

Any insight would help ENORMOUSLY.

RE: 2002 Blazer Battery/Oil Pressure Sensor Connection?
 

Maybe get your alternator and battery tested...