My 94 Dakota has 93K miles on it when last week, during freezing cold weather, the speedometer/odometer stopped working. Any ideas on what caused the failure and how to fix it?

 

Sure, I had this problem on my '95 3 years ago. The speed sender unit on the trans below the driver was out on mine. It's only available thru Dealerships or junkyards and was $50 (3 yrs ago at dealer), theres also a ground wire associated with the sensor that could have corroded, I had that issue too, I found the break right before the firewall on the driver side.

 

A few questions:
1. Can you provide more details on what the speed sensor looks like? Is it visible when looking underneath the truck?
2. Where's the ground wire? Engine side or inside the cab?

Thanks for answering my thread.