I have another tahoe, and i just had a new fuel pump installed. it seems a bit loud, but whenever there is a drop in voltage(turn signals, brake lights), you can hear the drop in voltage in the fuel pump. Please tell me what could possibly be going on...

What kind of fuel pump was installed.
Have you checked it for proper fuel pressure after replacing the pump?
What are the pressure readings?
Is the fuel pump getting proper voltage and ground?
What is the battery voltage reading with stuff turned on?

How is the fuel filter?

Check the electrical connection above the tank, the one near the left rear wheel opening (along the frame) and the ground lug at the same location.

Fuel pumps are very sensitive to voltage fluctuations, and a drop in system voltage will cause a drop in fuel pump voltage, and thus, a drop in fuel pressure. CMPI systems require fairly high fuel. pressure to operate, and a drop in pressure from undervoltage is NOT the fault of the pump. Dropping to 58 PSIG or lower may prevent the engine from starting.

I have another tahoe, and i just had a new fuel pump installed. it seems a bit loud, but whenever there is a drop in voltage(turn signals, brake lights), you can hear the drop in voltage in the fuel pump. Please tell me what could possibly be going on...



a loud pump is usually one that is likely to fail...shortly..

now the electrical load should have no effect on your pump or the dropping of voltage in your electrical system... what is required now is to find out why this is occurring.. with a meter check the volts at the alternator and at battery...with no load and then with every thing on...the voltage should remain solidly in the 13.5-14.75 VDC range...If it drops lower then you most likely need a new alternator , connections,or it is possible the belt is slipping..etc...


before replacing the alternator always have battery tested..and fully charged..