GPU Fan not working properly

Hello,

I had to replace my battery on my 2 year old alienware 15 r2, and now that everything is put back together and working, the GPU fan (left side fan) runs at a constant low speed and no longer adjusts to the needs of the computer. Before the battery change all was fine.  The company I had work on my battery I'm having check to make sure nothing is wrong physically with the fan. Any suggestions on what would fix this issue?

Thanks in advance!