ignition fault lamp - what is it telling me?
Discussion
Hi there,
Between the rmp counter and tacho my car has 2 little lamps, the upper one being red when "on". I understand this is a kind of warning lamp for ignition issue, according to the car user manual. I also understand that this lamp shall also quite normally lighten when starting the car during a couple of seconds, then stop lightening. The "issue" would be only if this lamp lighten up again during the drive...
My "situation" is as follows: at start is switches on and off as expected. During the drive, say 5 minutes after start, it switches on again, and stays a while, maybe 2-3minutes, then switches off, and comes back and back in a rather erratic mode. I have to say that I did not notice any change, noise, loss of power whatsoever when this lamp is showing its red color...
What is your experience with this little red lamp ? what could go wrong ? and how does it work, I mean what does trigger the switch ?
My car is a 1994 Griff 500, pre-serp.
Txs in advance,
C14
Between the rmp counter and tacho my car has 2 little lamps, the upper one being red when "on". I understand this is a kind of warning lamp for ignition issue, according to the car user manual. I also understand that this lamp shall also quite normally lighten when starting the car during a couple of seconds, then stop lightening. The "issue" would be only if this lamp lighten up again during the drive...
My "situation" is as follows: at start is switches on and off as expected. During the drive, say 5 minutes after start, it switches on again, and stays a while, maybe 2-3minutes, then switches off, and comes back and back in a rather erratic mode. I have to say that I did not notice any change, noise, loss of power whatsoever when this lamp is showing its red color...
What is your experience with this little red lamp ? what could go wrong ? and how does it work, I mean what does trigger the switch ?
My car is a 1994 Griff 500, pre-serp.
Txs in advance,
C14
There are potentially three warning lamps.
The ECU has a maintenance information lamp output that tells you it has detected a fault. I don't think it's normal for this to be wired up.
There is a 'no charge' warning lamp. This should come on when you switch the ignition on, go off once the engine is started. If you rev the engine and switch the ignition off you should see this lamp glow as the engine spins down, and then go out as the engine comes to a halt.
There is a 'low oil pressure' warning lamp. This should come on when you switch the ignition on, and go off once the engine is started. If you stop the engine without switching the ignition off, for example by disabling the fuel pump, the lamp should stay off as the engine spins down and then come on a few moments after the engine comes to a halt. Hence you can tell the two warning lamps apart.
If the no-charge warning lamp is coming on this indicates a voltage difference between the switched ignition supply and the alternator output. There should not normally be a difference since they are both connected to the battery +ve. Sometimes you can get a small difference if lots of things are switched on causing a small voltage drop in the wiring. This would usually cause the lamp to glow slightly, usually more obvious at night and getting brighter and dimmer as you switch headlamps and fan etc on and off. You will also get a voltage difference if the alternator is no longer connected to the battery, for example because the fusible link has failed. It's quite common for these to fail mechanically and produce an intermittent connection which would fit your symptoms.
The ECU has a maintenance information lamp output that tells you it has detected a fault. I don't think it's normal for this to be wired up.
There is a 'no charge' warning lamp. This should come on when you switch the ignition on, go off once the engine is started. If you rev the engine and switch the ignition off you should see this lamp glow as the engine spins down, and then go out as the engine comes to a halt.
There is a 'low oil pressure' warning lamp. This should come on when you switch the ignition on, and go off once the engine is started. If you stop the engine without switching the ignition off, for example by disabling the fuel pump, the lamp should stay off as the engine spins down and then come on a few moments after the engine comes to a halt. Hence you can tell the two warning lamps apart.
If the no-charge warning lamp is coming on this indicates a voltage difference between the switched ignition supply and the alternator output. There should not normally be a difference since they are both connected to the battery +ve. Sometimes you can get a small difference if lots of things are switched on causing a small voltage drop in the wiring. This would usually cause the lamp to glow slightly, usually more obvious at night and getting brighter and dimmer as you switch headlamps and fan etc on and off. You will also get a voltage difference if the alternator is no longer connected to the battery, for example because the fusible link has failed. It's quite common for these to fail mechanically and produce an intermittent connection which would fit your symptoms.
Thanks a lot for the hints and precise description, I will change the fuse as first suspect when I get hold of a 100 amp item.
I was also wondering if the missing plastic cover which protects the 2 wire connectors on the alternator could be also a cause. I tried at many place to find an exchange item, but it seems that there were a lot of variants... this part is said not to ordered as stand alone, but comes with the whole alternator ;-)...
C14
I was also wondering if the missing plastic cover which protects the 2 wire connectors on the alternator could be also a cause. I tried at many place to find an exchange item, but it seems that there were a lot of variants... this part is said not to ordered as stand alone, but comes with the whole alternator ;-)...
C14
LordGrover said:
fwiw my ignition lamp flickers at v high revs. Only noticeable in the dark but at about 5,000+ revs it glows slightly - not full brightness. It's done it for the three years I've owned it.
You look at the dashboard when you are doing 5000 revs? My word, you are a hero.
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