MG Car Repair: 1976 MGB Electrical, differential pressure switch, brake light switch

Question
On my 76 MGB with the ignition on, when I pull up on the emergency brake the starter engages the engine and stays on until I disengage the emergency brake. I've gone to the starter relay and the two WR wires in a single connector are getting power 1. from the ignition, 2. from the emergency brake light switch. There is supposed to be diode in ths line according to the wiring diagram. Looks like the voltage is passing through the diode turning on the starter. Where is it and what does is look like ?
John

Answer
Hi John, I don't remember ever changing one of the diodes out, but looking at the diagram you should be able to run a test that would confirm that the diode has failed by shorting the two wires of the brake differential pressure switch to see if it activates the starter relay also. My guess is that the diode is wrapped in the harness. I think BLM was sleeping at the wheel when they tied it to the starter relay. If it confirms that the diode is at fault and since it has failed by conducting current in both directions, if it were mine I would just add another good diode to the wire off of the starter relay by just IDing which of the two White w/red tracer wires it is on and put in a new diode (if you want to keep all those idiot proof lights they put in.) Sorry, I'm from that old school that says "Less it better". I was one of those who was disappointed to see roll up windows put in MGs. I was sure the next thing they added was large tail fins and large chrome bumpers with truck grills and electric heated seats.
Howard