QuestionQUESTION: Howard- I have a '73 spitfire and I have the following problem that I cant seem to figure out how to fix it.
First- Only my left turn signals flash. The front right turn signal stays on but does not flash. The back is off. I checked the bulb and connections and they both work. The interior indicator for the right turn signal stays on solid. My side running lights and brake lights do not come on at all. Head lights (low and high beams) work just fine. I checked the fuses and they are good. I don't know where to go from here. Any ideas would be very appreciated.
Thanks, Ross
ANSWER: Hi Ross,
You need to take a wiring diagram and a 12v test light and start testing circuits. Pick only one circuit that don't work and I like to start at the load (a bulb in your case) and follow the diagram and color code of the wire and test back toward the power supply a step at a time and you have to find the fault. Many times when you trace one circuit you will correct the others also.
If you don't have a diagram let me know and I will put one on my web site for you to copy.
Howard
---------- FOLLOW-UP ----------
QUESTION: Thanks Howard. I was afraid you were going to say that and hoped it was going to be one of those, "that happened to me once and I did..." I have a diagram from a 75 spit that I have been using and seems to be pretty accurate. If you have one from 73 that would be great.
Thanks Ross
ANSWER: Hi Ross,
Sorry, no magic bullets, just work. Go to my web site for a 73 Spitfire diagram and index.
http://mg-tri-jag.net/73SpitUS1x1.jpg for the diagram and
http://mg-tri-jag.net/73SpitUS21x1.jpg for the index.
Let me know how you do.
Howard
---------- FOLLOW-UP ----------
QUESTION: Thanks for the diagram. This is very bizarre and somewhat frustrating. I started by changing all of the fuses and that solved some of my problems with the running lights except for the front. There is no power to the right rear blinker and I tired everything to test everything I could get to and could not figure it out. I tried it turnsignal and there wasn't power which is odd because the other turn signals work except front right which will stay on when the signal is turned on. The horn doesn't have power to it either so I am thinking it has something to do with that cluster. Two more questions, does it mean anything when the interior gague lights act erratically (sometimes when I am driving they will just come on)? Is it possible that all of this could be linked to the wired coming into the fuse box? I know most of this you cant answer because it takes tracing them down, I just am having a hard time tracing them because of the big mess of wires under the dash. If I can I would like to start with some key areas that I can test and work back like that.
Thanks for all of your expertise.
Ross
AnswerRoss, You are trying to find an electrical problem by symptoms and that is all useless information. EVERY time you have an electrical problem just follow the yellow brick road. Meaning, pick a circuit that does not work and take your test light and test that (bulb in your case) and look at the wiring diagram and note the color of that wire and start tracing it back to the power source a joint at a time and you can NOT fail to find the problem.
The symptoms "If i do this it does this and if I do that it does this" Is 100 useless info in finding an electrical problem and fixing it.
The wiring diagram has the "Yellow brick road" of the circuit you are having a problem with. All you have to do is to take your test light and follow it to where ever the power is lost. That will ALWAYS correct an electrical problem and not waste a lot of time guessing what might be wrong.
Howard
