QuestionQUESTION: I replaced my broken handled turn signal switch assembly with another one. Unplugged the old one, plugged in the new one, reassembled to steering column etc. when I tried it out and turned on the lights, the right headlight (passenger side) went out, then worked on bright. The turn signals lit up on the dash in each direction when I turned the selector, but, didn't blink. shortly there after - smoke from the assembly. I figured I just bought a faulty switch assembly since it was used, so, i bought a new one, similar problems, but, no smoke this time... Help!
ANSWER: Hi John,
You have some major problems with you wiring and should not connect your new switch up as it is in danger of being destroyed if it is not already destroyed.
A fuse should have burned before anything should have smoked. You need to get a wiring diagram of the car and use a test light and you need a in-line 35 to 50 amp fuse and remove either one of the battery cables from the battery and connect the in-line fuse in between the cable and the battery post. This will allow you to test each circuit without the danger of burning up a switch or the harness itself.
If you don't have a diagram let me know what kind of MG this is and I will put a diagram up on my web site for you to copy.
Howard
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QUESTION: Thanks Howard, I have a 1971 MGB - standard issue... No emission stuff, OD, etc. Just an engine, and transmission - no bells and whistles. I will check my fuse box and see if there is a jumper or something from the previous owner that bypasses it. Who knows. I do have the wiring diagram from the workshop manual. But I am no electrical engineer - so it is Greek. I have a test light! The inline fuse seems easy enough. I was praying you were gonna tell me it was just some old grease getting hot! I bought two new flashers - they were cheap enough - but, I can only find one flasher on the car. Did I get took for two different models and only needed one?
AnswerJohn, there is a turn signal flasher and a 4 way flasher too. But not two turn signal flashers. The wiring diagram is just like a road map. You don't have to be an electrical engineer to read it. Just a magnifying glass sometimes and a colored pen.
Most but not all circuits are fused If you have something plugged in wrong or shorted you need to follow my directions. It is not rocket science, just work. I learned early that when you have an electrical problem just pick one circuit that has a problem. (In your case the turn signals) Find them on the diagram and mark them with a colored pen and follow the switch wires and mark them as you track them down. You will end up with several wires going in different directions and you will see that wires go to the lights and to the instrument light and to a turn signal flasher (this is the power supply) and the flasher gets it's power from the fuse panel.
I told you to purchase a in-line fuse with several 35 or 50 amp fuses and disconnect the battery and put the inline fuse between the cable and the battery post. You can't start the car now because the starter would just blow your in-line fuse but you can operate the turn signals so just follow the power trail from the fuse panel to the flasher testing as you follow the trail with your test light. Lucas color codes are very reliable on MGs so just read the diagram and at each point test the car. I usually start at the power supply and go toward the load (lights) Go one step at a time and you can't fail.
Howard
