spedo stopped working. possible tests before pulling it out?

[awd-rwd racer]

so my spedo doesnt work in my Fd. is there a way to test to see if it is the digital dakota or the spedo before i pull the gauges out? can i just put a a voltage tester on the out put of the dakota to make sure its giving a signal? also, my buddies laptop does read the speed while tuning if that helps narrow it down.

thanks

[MPbdy]

The DD box should have a solid green light sitting still and then a blinking green light while moving.