I need to buy a replacement cooling fan for my impala and notice there is a heave duty cooling option. How do I know if I need this or not. I have a 3.4 engine so I guess I would assume I don't need the heavy cooling option. Is there any way to check?

 

So I figured out which fan I needed but now I seem to have an electrical issue. It doesn 't run. I looked at the schematic and tested the relays and fuses and they all look good. Is there something else anyone can suggest? Does the temp sensor on the radiator have any role in this?

 

It tells that fan when to turn on, you could try turning on the a/c, it tells the fan on most cars to turn on then check the power to the fan. Good place to start.