In a message dated 4/30/98 1:06:07 PM Eastern Daylight Time, NikkiMW1@aol.com
writes:
> 1) The oil light will stay on at all times (so does the brake light).
Nikki,
As Andy pointed put, this is most likely a problem with the brake failure
warning switch. Try disconnecting the black/purple wire from the warning
switch and see if the lights don't go out. If they do, then you need to re-
center the switch. Go to the VTR web site www.vtr.org and then to the
maintenance page, and look for an article on the functioning of this switch,
called a PDWA. If the lights don't go out, then you probably have a short to
ground somewhere in this circuit. If so, disconnect the black/purple wire
from the back of the brake warning light and the light should go out. This
narrows your search to somewhere along the black/purple wires.
> 2) The headlights don't work at all (tried switching the leads on the
> headlight switch) but still no headlights.
The power feed to the lights goes like this: From the battery to the light
switch via a brown wire, from the light switch to the hi-lo dimmer switch via
a blue wire, from the dimmer switch to the high beams via a blue/white wire,
and to the low beams via a blue/red wire. There is also a purple wire going
into the dimmer switch to flash the high beams for passing. The purple wire
is fused; the brown wire is not (for a very good reason, BTW).
With a voltmeter or a test lamp, first look for voltage on the brown wire into
the light switch. If you have voltage, proceed; if not, look for a break in
the brown wire or switch connections. Next, with the switch on, look for
voltage on the blue wire. If you have voltage, proceed; if not, the switch is
bad. Now go to the dimmer switch, and look for voltage on the blue wire here.
If you have voltage, proceed; if not, there is a break in the blue wire. Look
for voltage on the blue/white and blue/red wires. One or the other, but not
both, should have voltage, depending on the position of the switch. If not,
the switch is bad. If you have voltage, then there is a break in the wires to
the headlamps themselves. You will have to trace the wires from the switch to
the lights, looking for breaks or loose connections. Watch for dirty,
corroded connections. You might want to disconnect each one and examine it
for cleanliness.
To check the function of the passing flasher, look for voltage on the purple
wire at the switch (both the purple and the brown wires are hot at all times,
key on or off). If you don't have power, look for a blown fuse in this
circuit, or a bad connection, broken wire, etc. Operate the flasher switch
and look for voltage on the blue/white wire from the dimmer switcher. If you
have voltage on the purple wire, but not on the blue/white wire, the switch is
bad.
Dan Masters,
Alcoa, TN
'71 TR6---------3000mile/year driver, fully restored
'71 TR6---------undergoing full restoration and Ford 5.0 V8 insertion - see:
http://www.sky.net/~boballen/mg/Masters/
'74 MGBGT---3000mile/year driver, original condition - slated for a V8 soon
'68 MGBGT---organ donor for the '74
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