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Regarding red light on dash

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mgbnew

mgbnew

Senior Member
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First off I would like to thank all those who responded to my dilemma regarding the red light on the dashboard. In reviewing all the suggestions I found that it was the oil level or so it seems, because after changing the oil and also replacing the valve cover gasket which was all twisted which was the cause of the oil leaking out everything seemed OK.
One question I do have is I was surprised at the number of responses questioning the location of the red light. The B is a 1970. The two and only two lights on the dash directly in front of the driver are Blue on the left (as looking from the cockpit) and red on the right. I may have been reading wrong but most replies were saying that the lights are reversed. If I ever figure out how to attach a picture I will show the problem next time. I think that is the easiest. Any thanks again. I really enjoy the discussions. /ubbthreads/images/graemlins/cheers.gif
 
I have a 75 and its set up the same. The blue is the high beam indicator. Through the years the B had several dash setups. I'm not sure of the exact number of cahnges, or when exactly, but as far as I can tell it was 3 different layouts. This is probably the reason for all the conflicting answers.

-D.
 
Thanks, it was a bit confusing but I think I have it figured out. The high beam light is definitely on the left and the engine light is on the right as I sit and look at the dash. They are the only light indicators on the dash. Still having the red light come on a bit. Will check the timing and the alternator. This site is really a great help. They are a lot of owners out there willing to help anyone with a problem. AS they say, “ those who drive an MGB are in a class of their own.”
Thanks again.
 
If it's the ignition light, check your fan belt tension first. If that doesn't do it, check your alternator, then voltage regulator and also check for bad grounds. The ignition lamp will often light up a bit at idle just because there is little current being produced by the charging system at such low engien revolutions.
 
Very Interesting...on my 74, and in the manual, when looking from the driver's seat, my ignition (red) light is on the left (next to the tach) and the high beam indicator (blue) is on the right (next to the speedo) above the oil pressure gauge.

It is not unusual for the ignition light to come on at very low idle, especially when the car is first started. The light indicates that the ignition system is on, but the battery is not being charges by the alternator. Steve's suggestions are right on the money for diagnosing.

Bruce /ubbthreads/images/graemlins/driving.gif
 
[ QUOTE ]
Very Interesting...on my 74, and in the manual, when looking from the driver's seat, my ignition (red) light is on the left (next to the tach) and the high beam indicator (blue) is on the right (next to the speedo) above the oil pressure gauge.

It is not unusual for the ignition light to come on at very low idle, especially when the car is first started. The light indicates that the ignition system is on, but the battery is not being charges by the alternator. Steve's suggestions are right on the money for diagnosing.

Bruce /ubbthreads/images/graemlins/driving.gif

[/ QUOTE ]

My dash is the same as yours, Bruce, his is the '68 through '71 dash with no glove box. I can't tell from any of my catalogs where they are supposed to be on the '70. My owner's manual shows my ignition light on the left.

If you have a volt meter, check the 12 volts with the engine running and reved slightly. If your alternator is working properly, you should get around 13.8 volts on the 12 volt line when you rev the motor a little above idle. If it remains down around 12 volts, your alternator isn't working right or you have loose belts. The internal parts of the alternator are available. In addition to the voltage regulator being a possible problem, the rectifier block could be the culprit. The last time my light stayed on, the regulator didn't fix it and it turned out to be one of the diodes in the rectifier block was open so replacing the block fixed it. The brushes are a good thing to replace while you are in there in addition to cleaning the slip rings the brushes mate with.

Also, Al, the red light has nothing to do with the oil pressure. It is strictly ignition/charging condition. It is dual purpose. First it tells you the ignition is on when you first turn the ignition on and second, after the engine is running a little above idle, it tells you the alternator is charging the battery by going off.
Bob
 
Refurbish? Refit? Diagnose sub-faults?

...and alternative would be a whole new alternator (did I also mention an upgrade to a modern high-amp unit?) /ubbthreads/images/graemlins/wink.gif
 
Thanks again for the information. This forum is fantastic, especially for new owners like me. I drove the B to work this morning so I can take it over to the mechanic who serviced it last time for me. I did take her out last night and yes the red light did come on but very low glow but it is definitely coming on. It goes of when I stop at a light and am sitting in the neutral. When cruising at say 30 kl, it is a faint glow coming on and going off but definitely there. I will have the alternator check this morning.
Again thanks to Sultanoswing, Bruce and everyone else for the information.

Al (newmgb)
 
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