1966 Brake / Directional Light Issues

Dear Bill,
I am writing to you in concern to a 1966 Lincoln Continental that a friend of mine is having a problem with. The problem is the rear passenger-side brake/directional light is staying on all the time and brake light switch was replaced and the problem still exists.
The driver’s side brake light/directional lights do not operate at all. I am asking you for insight so that this problem may be rectify.
Thank you,
Amado
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Amado –
The rear brake lights receive power to the left and right rear bulbs through separate wires (left and right) from the turn signal switch. When the brake sw. is activated power travels from the brake sw. to the turn signal switch and depending if the turn signal switch is engaged or not these wires to the brake lights may or may not both receive power for the rear brake lights. Your description of the rt. rr. brake light staying on seems to indicate a problem with the turn signal switch itself or the wiring to the switch. If all the rest of the cars wiring is intact etc. a good test for you will be to unplug the t.s. switch at the lower steering column and then observe if the rt. rr. brake light then goes off. If the light does go off and the wiring from the plug to the sw. is o/k a new switch may be needed. If the light remains on with the t.s. sw. unplugged the body wiring from the plug to the rt. rr. brake lights will need to be traced for a short etc. with the aid of the correct wiring diagram. The correct wiring diagram and good automotive elecrical knowledge may be necessary as this circuit on these 66’s can be complicated. Some vehicles have appeared at Lincoln Land with more than one fault and this of course makes diagnoses even more complicated. Keep in mind that a “four way hazard” flasher circuit as well as a brake light relay may also be involved in this issue. The turn signal switches though are usually the culprits with the symptom that you are describing. Also, there are two styles of turn signal switches on a 66 Lincoln depending on whether the car has a fixed or a tilt steering wheel. The installation of the switch for the tilt wheel style may be adjustable and if so should be checked for proper adjustment and operation before condemning the sw. itself.
I hope that the above helps you to a quick diagnosis. In the event that you require repair parts we will have these available for the job.
Sincerely,
Bill