Blinker puzzler

Often, the right brake light on our 86 in sig below does not come on with the left brake light. Not sure when this problem started, as we only see it if somebody in the family is following that truck.

But after actuating the blinkers, it fixes itself. For a while.

I reason that the fault must be in the blinker switch on the stalk. We recently installed a new plastic detent spring from fleabay to correct the blinker not staying on unless held on.  Anybody BTDT?

I have had similar problems with Ford and Chrysler turn signal switches. Problem seems to be a combination of wear and oxidation of the contacts in the switch. I would try some contact cleaner (Radio Shack used to have a good one) and spray it in and work the switch (you will need to remove the wheel to get at it fully). Beyond that it becomes new switch time.

I will second the contact cleaner. I use that stuff all the time when I pull any connector apart. Sometimes a lil dialectic grease will go on after cleaning, depending on the application..