QuestionOn occasion my 1970 MGB won't start - the battery is fine - the fuel pump is fine - it's just "dead". The red ignition light does not light up, and nothing electrical [lights, wipers, etc] will work. I've asked a local mechanic who says something like "who made that car?". My question is this: could it be the solenoid, or possibly the starter? What suggestion[s] might you have. I have had the car for 34 years - it lives in a heated garage - I need help!
AnswerHi Charles,
I worked for many years as a mechanic and mechanic's instructor. I never found it useful to try to think "What is Wrong?" I never found a car with an electrical problem that I didn't fix. (some quicker than others)
I use a method of dividing the car into smaller and smaller sections and I am always surprised at what I find and I never fail to find the problem with this method.
I can not tell you what is wrong but I can tell you how to find it. You need a couple of tools. One is a 12v test light and two is a wiring diagram.
My first question is, How did you know the fuel pump is "fine"?.
With a test light do this, turn the key to IGN position (not start) note that the IGN light is not on as you indicated. Go to the fuse box on the right fender well and test for power on BOTH sides of the 3rd fuse down. If there is no power go to the large brown wire on the back of the alternator and test for power on that wire. If there is no power, Clean and tighten all cable connections on the battery/s and on the starter solenoid and the battery ground strap. Than do the same tests.
Brown wires are main power sources for the system and originate at the starter solenoid.
If you have power at the brown wires then you have eliminated the main power source as a problem. Next in-line is the ignition switch and then the fuse box. Each test you run, you are dividing the electrical system into smaller and smaller sections.
Let me know when you have proceeded that far and what you found.
Howard
