Hello, I'm working on my kids ride on cars. He has two of them. On the first it was 6V and came with one motor on one wheel. I updated it to 2 motors, one on each wheel and 12Volts. I put in a DPDT switch so he could select high and low. On high the motors are run in parallel and on low they are in series. Works great. No issues. The other car came as 12v with 2 motors one on each wheel. It has a "turbo boost" button that switches between series and parallel like I did on his other car but it's a momentary switch can came from the factory that way. Works fine with the factory motors. But boys being boys and dads being dads... we want to go faster (and the factory gearbox died so I had to replace that anyway) so.... I bought two new "super fantastic, double whammy, gonna last forever" motors along with new gear boxes. When I installed the new motors.... on low, only one motor runs. The other motor runs for a second in one direction (I think it's reverse of the other wheel) then changes direction and then stops completely, all at the same time, the 2nd motor runs in forward all the time fine. As soon as we hit the turbo boost, both motors run fine in forward. The problem is, in non-boost (series) it's a total one wheel wonder. The factory motors did not do this. Both applied power equally to both wheels. In this first car that I modified to have 2 motors and switch from series to parallel, it works fine, both motors drive equally regardless of how it's wired. The company I bought the "super fantastic, double whammy, gonna list forever" motors says this is normal. My basic understanding of motors (and experience with both cars) is this that this is not normal. Can someone explain to me what is happening and maybe how to fix it? As a one wheel wonder it's useless. It just sits and spins the one wheel and does not go anyplace. Thank you!