You should always use a relay when installing a high current draw accessory like this, even if you use a manual switch. Mine uses a relay activated by a coolant temp switch installed in the intake manifold.
I need help with ordering this part. There are choices to make at Rock Auto and I am clueless as to what to order... For example:
Have to choose between the HHR LS or HHR LT.
Then have to choose between the 2.2L or 2.4L application.
Finally, I see that it states 'for AC cars'. Does this matter if I don't have AC?
Did you purchase the 'relay activated coolant temp switch' from Rock Auto as well?
Any Part Numbers and part list would help.
Thanks