My speedometer has worked sporadically for the past few years. It works for a few months, then all of a sudden it doesn't. It seems to not work more in the summertime. It stops working often time for a few weeks. It works for a few seconds once in a while only to stop working. Then it will start working with no problems for months. (Example, it did not seem to work almost all of August but since October it has worked every single day up untill yesterday. It seems to "fall" like its working and all of a sudden it just falls to one side or the other.
Also, when the speedometer is not functing both the odometer and the gas gauge do not function as well.
I'm not sure if it makes a difference but I like in Western wisconsin and the summers are very humid and hot while winter is very cold and we get alot of snow?