That component is the voltage stabilizer. It has nothing to do with the
turn signals but it does provide the supply voltage for the temp and
fuel gauges.

It is a 10 volt regulator. It takes the variable 12-14 volts from the
battery circuit and turns it into a stable 10 volts for the 2 gauges.
This prevents them from reading differently under various conditions.
Without it the gauges would read differently at night or when the heater
or headlights were on.

Mark

 Jim Felder wrote:

> I just removed the instrument cluster (didn't come with the car, I
> bought it on ebay about a year ago because it had an accurate fuel
> gauge) on my 83 diesel westy. Looking at the back of it just then
> when I brought it inside for safekeeping, I see that behind the clock
> side, on the back of the nacelle, is a connnector block on one side
> and an electronic component, affixed with a single screw, on the other.
>
> It is this electrical component I am asking about. It has three leads
> coming out of it, two of which are messily soldered two leads coming
> out of the blue cable. The middle of the three leads is connected to
> nothing. I can make out the letters TCA 700Y on the component, but
> other numbers are unreadable.
>
> What is this, and does it have anything to do with the fact that my
> temp and turn signal LEDs don't work?
>
> Thanks,
>
> Jim
>
>