Odometer Stopped working

I have a '88 Volvo 240 DL automatic and I noticed about a week ago the odometer stopped working. The speedometer is working fine. This is not good because the car is no longer keeping attract of how many miles I have on the car. Is it a wiring fault?

It's not electronic, it's mechanical. They used nylon or plastic gear wheels in the thing, and it's routine for them to fail. Replacement kits can be found here:

http://cgi.ebay.com/ebaymotors/1986-1993-Volvo-240-Electronic-Speedometer-gear_W0QQcmdZViewItemQQcategoryZ33678QQihZ007QQite mZ170228419168QQrdZ1QQsspagenameZWDVW