Motorcycle Repair: 2002 Harley Sportster Speedometer, harley sportster, speedo sensor

Question
I think I messed up-I replaced the stock speedo and tach housing-with chrome ones.Instructions said to disconnect battery first-of course I didnt think I needed to do THAT.Unhooked speedo and tach-put them back together with the new housings and now speedo dosn't work. Took to dealer-told them what I did-they did some kind of tests and said speedo is dead-I need a new one. Could I have really messed it up that bad just by not dis-connecting the battery? I heard about problems with the speedo sensor before. Could this just be the sensor or do I have to buy a whole new speedo?--MANY  thanks

Answer
There are several tests that can be performed by a dealer. The problem with you doing it you dont have the equipment.
I dont think what you did was wrong. Yes you should have disconnected the battery, but not doing that shouldnt have hurt anything. When the key is off there is no power going to the speedo. Check your wiring to make sure the connections are making good contact. Other than that if the speedo is dead, like the dealer said, then it will have to be replaced. You might want to check with another dealer to get a second opinion.
Good luck and happy riding
Mike