hello all

i have a 1990 4x4 saph and have been having intermitent hesatation problems which i think are electrical . i traced a problem to the rev counter when i unpluged it the car ran fine got the new part fitted it but the prob is still there then we decided to check the voltage at the fuel pump and the coil the voltage at the fuel pump drops to 9.5 when the fan comes on or when the power is drained by lights and stereo with 4 ways on so should we rewire the fuel pump in case the wire has gone bad or what else could it be the battry is fine so is the coil

what you think