I was at my first car show today and everything ran great but on the way home I noticed my fan quit working. I tested the fan and it's fine, the fuse is good.....now what.

Is there any way to test the sender, I suspect that's it cause it's cracked (overtightened it) and a little lose. I can't see any other problems other than a faulty relay but would that just quit after two days.

Help please!

Thanks,
Sean