japek

so my car (99 civic dx) is over heating way too much when im driving, when at idle its fine, sometimes when im driving it heats up but then it cools down by itself.
Ive found out that my radiator fan does not work, there is no power getting to it but the relay is new and the fuse is new but i connect it directly to the battery then its fine...The funny thing is that when i replaced my motor, I did not connect a ground that connect to the tranny so the car wouldnt turn on only the radiator fan would..I am so stumped on this..any help would be great..
Thanks