Question
66MGBGT-OD-switches.jp
QUESTION: Looking from above the gearbox towards the front of the car I see 2 switches. Which one is the overdrive switch, the one to the left or to the right side of the gearbox? Does the (yellow/red) wire run from the overdrive relay through a connector, to the one side of the switch and then another (orange?) wire from the other side of the switch to the overdrive solenoid?
ANSWER: Hi Johnnie.
When you select reverse gear you move the gear lever to the left and back. The bottom of the lever moves to the right and forward, operating the switch (2) on the right. The wires to this switch are both basically green, but one of them will have a brown stripe.
The overdrive only operates when you have selected 3rd or 4th gear. The lever is moved to the right, so the bottom of the lever moves to the left, operating the switch (1)on the left via an internal plunger.
When you operate the overdrive switch, you provide power to the yellow wire. If 3rd or 4th is selected, this power is passed through the switch to the overdrive solenoid. The actuating wire is usually covered in red braid.
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QUESTION: Thank you very much! So my car is a 1966, but although it does not have reverse lights on the body, it has the reverse light switch on the gearbox like the 1967 cars. Maybe because it was built 26/27 Oct 1966 according to the heritage archive.
AnswerAccording to my factory parts manual, every early MGB with overdrive had reversing lights.
The very early cars without overdrive could specify them as an option. They therefore had a threaded hole for a reversing light switch, but if you didn't specify the option, you got a blanking plug screwed into the hole!
I am guessing, but very early MGBs without the necessary oblong holes probably had a Lucas reversing lamp bolted underneath the rear bumper.
