VNH5019 Motor Driver Shield help needed


i recently purchased the VNH5019 Motor Driver Shield to drive two seperate DC motors, however i cannot seem to get any response out of the outputs M1A / M1B… M2A / M2B it works perfectly. I am using it with a Arduino Duemilanove, with an external 24v power supply feeding the shield and the motors, running the sample code from the library. Using a voltmeter I don’t get any output on the M1A & M1B pins… I am not sure how to proceed, is it possible the shield is faulty? should i try amending the library to remap the pin configuration? I have nothing else plugged into the arduino…
any help would be greatly appreciated.


Could you please post pictures of your setup that show all connections? Also, could you include a clear picture of the bottom of the motor driver shield?

It sounds like the input voltage of your system is right at the maximum input for this board. Each of the motor drivers has its own over-voltage protection circuit and with an input voltage this close to the their limit, only one protection circuit might be getting triggered (which might explain why a single motor channel is not operating). Could you try using a lower-voltage power supply?