Jim,
When the headlights turned off, were the dash lights still on? If so, then the light switch is getting power. Look at the connections on the back of the light switch. It could still be a bad switch. The headlights and the bucket relay both get their power from the headlight switch (on a separate switch terminal from the parking lights).
If the dash lights go off also, then either the switch is losing power or the switch has a problem.
John
PANTERA INTERNATIONAL
A DE TOMASO CAR CLUB
Presents the De Tomaso Forums
The On-Line Meeting Place for De Tomaso Owners and Enthusiasts From Around the World
Clicking on the banner will take you to the sponsor's website.