fuel gage and also speed doemoter on 1991 Jeep Wrangler

we have replaced the fuel gage but cant figure out what wire goes to it ?! i dont know which one it is. and also i have a speed odemter doest work did but didnt the next day and still dont what could be the problem? plz help

1 answer
The fuel gauge usually has a blue wire, sometimes with a white tracer stripe on it. The speedometer could be your vehicle speed sensor located in the tailshaft housing on the transmission.