2001 Chevy S-10 No 12V to fuel Pump Relay and temp gage abo

I have been working on this truck for two weeks now. Here is what I know: 12V at Batt. With no key in temp gauge reads over 100. Hit the odometer switch and the temp gauges falls back to 0. This is due to a lose of the class two data signal to What and where? With the ignition in the on position the fuel pump realy power as 0 volts for the coil. I have jumped the 12V straght to the pump ( Pump runs but no start ) Currently I have the Dash apart hopping to come across a lose wire. No such luck. I bought this truck for $1500 its very clean but i have not drove it yet! PLS HELP!