I have a PWM motor taken from a dremel tool which draws up to 4 amps that I would like to control with the Arduino motor shield. Each channel of the motor shield is supposed to be able to provide 2 amps. Can I hook up the two channels in parallel by connecting the two positives, negatives, and PWM pins together to get a 4 amp output for one motor?
Which motor shield - provide a link, please.
It sounds like this motor shield is likely an L298 based device - is this correct? If so, then -in theory- you can parallel the inputs and outputs, similar to how you are saying - but you have to see if the shield allows for this. I have seen some shields that wouldn't, at least not without modding the shield somewhat. So - if we can know which shield you are using (and hopefully have a schematic for it), then we can look at it, plus the docs for the L298 to determine if it's going to be simple to hook up, or something more involved.