[TR] Turn Signals on a TR-6

[Ann and Tim Buja]

George E Killinger wrote:
> The Driver's side turn signals (both front & back) on my 1972 TR-6 will
> not come on.  The passenger side is fine, and when the hazard flashers
> are turned on, all four lights work.  Based on that, I don't think I have
> a bulb or flasher problem.
>
> Thoughts and recommendations?

Change the bulbs front and back on the driver's side.  As non-halogen bulbs
age, the tungsten filament evaporates onto the inside of the glass bulb.
This darkens the bulb (or can even turn it silver, in extreme cases) and
decreases the cross sectional area of the filament, which increases its
resistance and decreases the current flow through the filament.

By design, the original equipment Lucas turn signal flasher is a
current-sensitive device.  Increasing the load shortens the "on" time, while
decreasing the load lengthens the "on" time.  The turn signal flasher was
intentionally designed this way so it can let the driver know when something
is wrong with the circuit, such as a burned-out bulb.  Removing one bulb
will decrease current flow to the point where the flasher will turn the
remaining bulb on but won't flash it.  Your existing bulbs have probably
aged to the point where the combined current is no longer sufficient to
flash the bulbs.

In contrast, the hazard flasher is a current-insensitive device that has a
fixed flash rate for 1, 2, 3 or 4 bulbs' worth of current.

While you're changing bulbs, you might want to consider changing the
passenger's side bulbs as well.

Tim Buja - Rockford, IL - 80 TR8, 73 Stag, 72 TR6