GM-GMC: 97 Chevy Express Van, digital odometer, chevy express

Question
When I started yesterday the service light was on and digital odometer wasn't on. I started driving and trans felt like it was slipping? Had no symtoms day before. I did tow a small trailer and it burnt signal bulbs when first hooked up so I think it shorted something?

Answer
First question first was the speedometer working at all if not the speed sensor is either bad or unplugged that would be a likely culprit for the trans to slip because it is electronically contolled.did you pop any fuses when hooking up the trailer? I would check the tailer first for wire grounding out.