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MG MGB Technical - Headlights Dim

Hello, again. I have a 1976 MGB that has dim headlights. I am thinking that the chassis ground may be corroded and needs cleaning. Only problem is .... I don't know where the ground may be. The ground wires go into the harness and there seems to be no ground that comes out to a bolt or screw. Can anyone tell me where the grounding points are in the car.

Thanks.
C.R. Tyrell

Right in the area of the fusebox/coil, a 10-32 Posi screw with black wires on it.
Other major grounds are above the wiper motor for everything on the dash, and the license plate fixing bolts for the rear lamps.
Search for "bullet connectors" and "headlamp relays" for lots more!
You may as well order 10 single and 20 double connector sleeves from British Wire, or Moss - you need them - and it is cheap and effective.

FRM
FR Millmore

I was looking in that area for the chassis ground but so far not found. I will continue to look for that 10-32 screw. Thanks for the info... wiring diagram doesn't help much there. I think I will have a job for months cleaning bullet connectors!
C.R. Tyrell

Might be worth applying a 'temporary' earth at the lamp end first. If they then come on brighter then its the earth side. if still dim then you have a 'drop' on the supply side.
Bernie
B Anderson

Get two relays and wire them in . Plenty of info on the web
Forget the earth wire -just another undersized waste of time .
Wire new earth from right into the backof the bulb holder and connect to earth in front of the radiator (drill and put in self tappers )
This will cut out about 10 feet of wire and one poor little light switch
Put on dark glasses and stand back !
Then buy Halogen lights and your are in 21st Century !!
Andy
ap lestocq

If you can't find the earth point in the engine bay, look under the wheel arch for anchor nuts. The 10/32 screw will be attached to one of them. I don't know, but I doubt both headlights would use the same earth point.
Are the headlights dim on hi & lo beam ? If so,the problem could be on the input to the dip switch which comes from the light switch.I'm also in favour of using relays.Barrie E


B Egerton

All the lights in the front of the car are earthed through wires which join merrily together and go back and get screwed at that anchor point, And, there are normally a couple more earth leads there.
And while I am a leading proponent of relays, half-assed fixes such as self tappers are NOT the way to do it. I use ring terminals at the front wing mounting bolts for earths, one on each side, and these are also connected back into the main earth lead in the harness.

FRM
FR Millmore

Found the ground. Cleaned it ( was corroded) Lights brighter but since they are the originals they are "dim" compared to new bulbs. I thank all for their input. Missed seeing the ground as it was hidden under the attachment clip and the harness.
C.R. Tyrell

I'm just refitting the engine bay on my '67 and I don't recall seeing a ground in there.
Dave O'Neill2

This thread was discussed between 19/10/2012 and 20/10/2012

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