MG-Cars.info

Welcome to our Site for MG, Triumph and Austin-Healey Car Information.

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGB Technical - Ignition Warning Lamp-1967

Hi Folks:

During troubleshooting a non-functioning passenger side turn signal problem. I noticed that the ignition warning lamp was out with ignition key switched "on" without engine running. A few questions?

1. If the lamp is burned out; what is the replacement P/N? & where to buy it.
2. Could the problem be associated with the generator control box, since the green/brown wire goes from the lamp holder to the "WL" terminal on the control box?


Thanks: Ricb Boris 67 B
Rich Boris

You will have to check the bulb with an ohmeter, I have no idea as to replacement part but expect one of the suppliers does, if not you may have to buy a 12v 1 or 2 watt pea bulb and fit it somehow. The ign light is wired across the cut out (= between the dynamo and battery)so when the dynamo volts exceed the battery it is shorted out as the cut out pulls in and charging starts. You could measure volts from wl to battery on the regulator. If you see 2 or 3 at idle, 12 with engine off and ign on and 0 with engine at 1000 + rpm then your problem is the bulb or wiring to it.
Stan Best

Any break in the circuit from its white at the ignition switch to the brown/yellow at the control box could cause it, including the bulb, plus possibly other things if the dynamo isn't charging the battery as it should.

Unplug the bulb holder from the back of the tachometer and you will probably find it is a screw-in bulb, 12v 2.2w, probably item 15 here. Should be the same in the main beam warning and gauge lighting, so swap one of those in to see if it is the wiring or the bulb. This assume original harness, current replacement harnesses use wedge-type bulbs.
PaulH Solihull

Hi Folks:

Found the problem; the control box "E" earth terminal was floating because of an open earth wire in the main harness. I added a new secondary earth path to the control box and the charging system is back to normal function. I also found the lamp for high beams on speedometer burned out; replaced and working correctly.

A question regarding turn signals: would a burned out bulb on the dash (right indicator arrow) cause the right turn signal lamps to not flash? Left side is working fine.

Thanks: Rich Boris
Rich Boris

No. It doesn't draw enough current to affect the flasher. RAY
rjm RAY

Are the right side corners glowing but not flashing? Or not glowing either? The latter would be be problem between the switch and main harness, either the switch contact itself or where the green/white wires join in the multi-plug by the steering column.
PaulH Solihull

Hi Folks:

Problem resolved; had an open in the turn signal switch harness. Replaced the switch from my spares from my old 66B. When I have the time I will try to repair the discrepant switch.

Thanks for taking the time to respond to this issue; much appreciated!


Thanks: Rich Boris 67B
Rich Boris

This thread was discussed between 19/09/2010 and 21/09/2010

MG MGB Technical index

This thread is from the archives. Join the live MG MGB Technical BBS now