On Monday, 10 February 2020 00:31:52 UTC, Adam wrote:
My car's blower motor relay may be bad (or the cause of noisy fan). So I
found the following video...

How to Test a Relay the Correct Way
https://www.youtube.com/watch?v=ire7vyDqelg

However, I don't have a cordless drill battery (used in the video).
Will the following battery charger...

UPG D1724 Sealed Lead Acid Battery Charger (6V/12V Switchable Single-
Stage With Alligator Clips)
https://www.amazon.com/gp/product/B0...c_act_title_1?
smid=A10QFO4IXVZNRN&psc=1

work ? Other frugal ideas ?

Nearly all relay failures are switching points gone high resistance. So test that. To power the coil... you have a car battery right?