My 2004 trailblazer only had 59,000 miles on it when the speedometer began not working. some times it reads i'm going 80 when i'm at a stop, other times (maybe one day out of 10) it works fine for about a day. the fuel and oil gauges are also not working correctly. the fuel says it is past full until it's completely empty and the oil does the same. the check engine light also comes on a lot for no reason. i also have a right tail light and blinker out even though i have had the bulbs changed. i have had a mechanic look at the wiring/electrical and can not find a problem. the estimated total repair costs are $1100 so far. *tr