As mentioned in another post, looks like my electricians did not wire the pump correctly. I need some help figuring out what I need to do in order to get high speed.

I have the Pentair Dynamo with a built in toggle switch on back. The electricians installed a 3 foot cord for me which runs to a 3 prong twist hooked into an intermatic timer. Looks like I am getting low speed just fine, but cannot get into high speed. Any help would be greatly appreciated.