Did a full tune up on a 1998 Blazer 4.3 and was running great. Dash gauges were normal. The pump sounded normal. A week later would not hear the pump and no start. I had tapped the wires going to the sending unit and then it would start. That quick fix stopped working and I needed a tow to the shop. There the mechanic replaced the wire harness. Pick the Blazer up today and when starting the pump had a much different sound (much more noticeable) and the battery gauge barely moves. Takes a few minutes to get to 14+, both oil and battery gauges fluctuates at idle and acceleration more so than before (to the negative), oil gauge needle is at 20+ when not running, poor gas mileage, exhaust has an odd smell, idles rough, wants to stall when stopping, electric pump has a whining and grinding sound. Not the steady buzz I'm used to. Could there be wires connected incorrectly?