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