QuestionI have a 1974 Triumph TR6 and I just replaced the battery and the voltage regulator because the car was over-charging and cooked the battery. After doing so, and before I started the car, I noticed that the ignition light was lit. After starting the car, the light goes out and the voltage gauge appears to be reading around 14v, previously, the meter was at its maximum. Any advice as to why the ignition light is lit when the car is off would be much appreciated. Thanks.
AnswerA charging battery will always be around 13-14 volts, so you should be OK there. Put a volt meter across the battery terminals at idle, and you should see a voltage in that range. If so, all is good.
I can't remember how my TR6 behaved before I stripped out all the wiring and replaced. Some cars are designed to show a light that the ignition is on, but you have not started the car. On a TR6, I can't remember if that is a normal condition, but I believe it is.
Below is a link to a TR6 wiring diagram. There is a diagram for each year.
http://www.advanceautowire.com/tr2506.pdf
What that light may actually be, instead, is an alternator warning light. Which means when the light is on, the alternator is not putting out enough voltage (low voltage condition). That is consistent with what you are seeing; before the car starts, no voltage from the alternator, so that side of the light sees ground, and the lamp lights. When the alternator is running, the voltage isn't gnd, so the light doesn't have a ground and turns off.
Sounds like it is operating normally. Check your owners manual to be sure about the purpose of that light; on the 74 diagram I couldn't find an ignition light, but there was the alternator warning light. You should be able to trace the wires, and verify the color coding of the wire to know if that is indeed the alt warning lamp..
Good luck
