Just had the same problem! Took the pass. wheel off, the front splash shield off. At that point you can see the head light connection to the main wiring harness. Take that apart and clean the connections. Worked for me! Give it a try!
Good Luck
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.