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MGA High beam indicator light not working

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Alex Grant

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High beam indicator light does not come on when high beams are switched by the dimmer switch, can’t figure this one out, any suggestions ? All wires are attached to dimmer switch and headlights and the bulb for the indicator is in good shape. At one point it did work now nothing.
 
So you're saying the high beam works in the headlights, but the indicator light doesn't?

Could be a burned out bulb - or some oxidation in the bulb socket. Pull out the bulb, check it for continuity, and clean that socket (steel wool, etc.)

Tom M.
 
See here: http://mgaguru.com/mgtech/electric/circ_d.htm
If the high beam lights work, then the issue can only be between the dipper switch and the indicator lamp. There is only one Blue/White wire (smaller than the one going to the headlamps), and no connectors in line other than two ends of that wire. A test light is your friend. The high beam indicator lamp has to be grounded through the speedometer. Each of the four dash instruments should have a black grounding wire from the harness attached to the thumb screw on the mounting bracket. Only one of the instruments is electrical (just the fuel gauge), but all of them need ground for the illumination lamps and indicator lamps. If those black wires are connected to each instrument, the dash panel does not need to be grounded on the car body.

You might otherwise find the dash panel itself is not grounded, especially if everything was well painted during restoration work. There are plenty ways the dash should be grounded (except for paint). The instrument mounting brackets may or may not make electrical connection where they touch back of the dash panel. Lower dash panel braces may or may not make electrical connection at the dash or at the heater shelf (again due to paint coverage). While you're at it, see if the turn signal indicator lamp and map light work (when parking lights are on). Those lamps do need to be grounded through the dash panel, so you may need to scrape some paint to make electrical contact to the dash.
 
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