i have recently bought a used 1996 Mustang GT. the previous owner took out the clock and added a 2 pod dome. it had endine temp and oil pressure. he hooked up the engine temp and partly hooked up the oil pressure one. the ground and ignition wires were hooked up but not the oil sender. i unhooked everything. i then whent to the cluster harness, i cut the 3 wires from the harness and hooked them to the aftermarket gauge. i turned the car on and it shot right to 100 psi and wont move. the new gauge is an electronic gauge. what am i doing wrong? please help me i am getting very frusterated.