Hello Robert,
Might also be the hazard relay unit. I am not sure of the location in a 2000 TC, but if it is the same as in the 3500/3500S, then it will be accessable from inside the driver's (on a R/H drive car) glove box.
If original, it is a small metal can with Lucas written on it, retained by a bracket on the body. There is also one for the flasher lights positioned next to it.
Ron.