2004 Thunderbird Sport turn signal relay repair


Symptoms: blinker lights would not flash and there was a loud buzzing from the flasher relay.
Somehow the flasher relay filled with water while it sat over winter.


With the cover removed, I found the leads on the capacitor had disintigrated:



The capacitor markings were still intact and it is a 3.3 F radial electrolytic capacitor, 50V.
I replaced it with a wet tantalum (more accurate) 3.3 F capacitor:

Problem solved !!!

I did a little research on the strobe IC chip, which is a U2043B: .pdf file One can speed up or
slow down the speed the blinkers flash by using a higher or lower value capacitor. This would be
useful when converting to LED's to slow the flasher speed back to normal. A higher capacitance
will slow it down and a lower capacitance will speed it up. One could also tweak the resistor value
for the same effect:

The spec sheet for the IC chip says it has built-in burned out bulb detection, so I tried it out by
removing one of the bulbs, and sure enough the blinkers on that side doubled in speed.

If you don't want to mess with repairing the old flasher relay, the Triumph part number is:

5558631-001 list price = $64.47

Electro-mechanical Hella and Wehrle (and perhaps numerous other brands) are available for about $10
and the 3-prong unit is used in the 1971-1979 VW Beetle. The lug markings on the back are 31, 49, 49a
(exact match is important)

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Donco, '04 TBS

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