Probably a slightly bad connection in the ignition switch, or the white or
brown circuits either side of it or to the alternator, or indeed a blown
(open-circuit) alternator diode, the light can glow brighter the more
electrical things you have switched on, and is more noticeable at night of
course.
The ignition warning light acts as a balance scale - as long as it has the
same voltage both sides it will be dark. This can be zero volts i.e. when
the ignition is off and the engine is stopped, or around 14.5v i.e. when the
engine is running and the alternator is working as it should. These
voltages are sensed on the white coming off the ignition switch, and the
brown/yellow coming off the alternator, if one is higher or lower than the
other the light will start to glow.
When this is happening measure the voltage on the white circuit (which needs
to be at the ignition switch or ignition relay depending on year and
market), the brown at the alternator, and the brown/yellow at the
alternator. If you get a potential different between the white and the
brown the problem is bad connections from the alternator down to the
solenoid, and back up to and through the ignition switch or relay. But if
those two are much the same and it is the brown/yellow that is higher or
lower than the others, then it is an alternator problem.
Slow wipers can indicate problems in all sorts of areas, like bad
connections anywhere in the brown, white or green circuits, but also
mechanical problems in the motor, rack and pinion, or wiper wheelboxes. The
problem with wipers is that bad connections will cause low voltage at the
motor, which causes slow speed, which causes higher current than normal,
whereas mechanical problems cause high current, which causes lower voltages
than normal. Which, can be difficult to determine. However purely
mechanical problems shouldn't cause the ignition warning light to glow, if
the electrical connections are good. But then you could have both!
PaulH.
----- Original Message -----
> Driving home last night, I saw a very faint glow in the ignition warning
> light. It was raining, it was dark, and I had the radio on. I have a
> decently sized alternator, so this is not a situation where I normally
> think I
> would be overloading it.
>
> After a few miles of travel, I determined the glow went away when I turned
> off
> the wipers, which have been a bit sluggish anyway.
_______________________________________________
Support Team.Net http://www.team.net/donate.html
Mgs@autox.team.net
http://autox.team.net/mailman/listinfo/mgs
http://www.team.net/archive
|