Hi Bobby, No idea where the diode is but a diode basically is a device that only lets electrisity flow in one direction. You can check if a diode still works by checking the resitance of the diode (while its not wired up to the circuit). Measure it one way and it should show a very high resistance, turn the wires around and it should show a very low resistance. If a diode is broken it usually doesn't let any current flow in any direction so it could very well be your problem. Hope that helps, Bastiaan Olij home: http://mux.speed.planet.nl email: mux@xxxx ICQ: 35645433 1989 Porsche 944 S2 (for sale) 1981 Delorean DMC-12 vin 4597 1988 CRX (fixing up just for fun) ----- Original Message ----- From: "BDM" <bmims1@xxxx> To: <dmcnews@xxxxxxxxxxxxxxx> Sent: Sunday, September 08, 2002 2:42 AM Subject: [DML] What is a Diode? > My passenger door wiring has no power. I have removed the T-Panel on the top and cleaned the roof plugs. I have verified continuity from the roof plugs to the door harness wiring. I have verified the wiring continuity from the door light switch to the lights in the door. > > I have a wiring diagram and I suspect that the diode in the circuit is faulty. However, I do not know where it is located nor what it looks like. How do I check the diode and are the difficult to diagnose?