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Ignition warning light?

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M

Millrat

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My question is this: Is the light warning me when it is on or off? We have only had the car running the last little bit and the light has been on the whole time. The battery has not given us trouble and the car starts readily and runs well. 62 Sprite MKII but it may have had the wiring tweaked at some point. The light is on the tach, but the diagrams I have show it on the speedometer. I have the older mechanical tach. Is it possible that in changing an ignition switch or switching around the wires that the system is still charging but that the light is on? Next step is to find out if the generator is putting out and how the *#$#*(translated idiot) light works!
 
Well if the light in the speedometer goes on and off when you have the lights on and push the dimmer switch then you can be sure you have a charging problem!

Kurt.
 
I meen no one has wired the tach and speedo backwards. The ignition warning light should go out after you start the engine and bring the revs up a bit. If it doesn't you may have dirty contacts in your regulator or bad connections or sticky brushes in your generator. Those are the easy and cheap fix's. You know what comes next!

Kurt.
 
That's the light! Doesn't go off when you rev it a bit, charging system most likely needs attention as indicated above!
Dave
 
Just to be clear, though often called an ignition light, it has nothing to do with the ignition system. The "red" warning light will be for the charging system as mentioned above. It would more appropriately be called a "charge warning light".

When everything is happy the light should behave as follows:
1) key out, engine off, light = off
2) key in the run position, engine off, light = on
3) key in the run position , engine running, light = off

You said the car is running fine but that you have only had it running for a short while. A fully charged battery in good condition will typically have more than enough power to start and run the car for a few days of limited use driving. Do not assume everything is OK because the car starts and runs.

Make voltage measurements at the battery both with the engine off and running. You should see about 12.5V across the battery with the engine off and anywhere from a 1 to 1.5V increase when the engine is running. If you do not see a voltage increase then the battery is not charging. If you see an increase to something over 15V, the battery is likely overcharging and that can be damaging to the battery.
 
So my conclusion is that I probably have been running on the battery the entire time without charging. I will follow all the good advice and see if I can turn out the light.
Thanks!
 
Can be anything, really. Other than a bad bulb or wiring for the bulb. Grounds, brushes, armature, control box, wiring between generator and regulator.
Dave
 
I went through a similar situation last summer. I suspect the charging system is not working and you are running exclusively off the battery. After many hours of troubleshooting, it was the voltage regulator. I have since learned that this is traditionally the weakest link in the charging system and probably the best place to start. The manual has a set of test sequences to determine if this is the source of your problem.


John
 
Before we all go nuts, you said that the wiring may have been tweaked and the light is on the wrong instrument. Of course, it's easy to hook it up to whatever lamp some PO wished, but for starts please make sure you're looking at the ignition lamp and not the high-beam lamp. The voltage measurements that Doug suggests should tell you for sure it the thing is really charging. Use an analog meter to do this measurement, if possible, because electrical noise in the system can upset a digital meter.
 
Pretty sure now that I am looking at the correct light. Lots of corrosion on one side of the voltage regulator, so it may be there. I will continue to test away. The learning curve has actually been kind of fun. By the time it's over I will know each wire and connection personally.
 
I believe in Lucas wiring schemes you will find that the "IGN" warning lamp has a 2-wire bulb socket. A white wire will leave one side of the socket and go to the ignition switch and a brown/yellow wire will leave the other side of the bulb and go to the control box. You can at least look behind the dash to see that the lamp behind the red lens has the correct color wires to confirm a PO didn't move the lamps around.
 
Mine has two white wires. The diagram that fits mine the closest shows three white. The brown and yellow runs from generator to control box. From there I am having to scarpe paint from PO, but all seems correct in this area or at least not obviously tampered with. It's a little tight under the dash
grin.gif
.
 
Sometimes a little spray carb cleaner on a rag (sprayed away from painted surfaces) then rubbed on wiring will clean off the overspray.
 
Thanks for the tip. The whole engine compartment including the engine was painted red thirty years ago by the PO. As I go I find little things that should be other than they are. Wires connected to the wrong spots, a negative ground radio in a positive grpound car, etc. I learn something new every day!
 
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