RRS1,
You can very easily find out if your rheostat is causing your dim gauge illumination problem. Just remove the two contacts from the rear of the rheostat and hold them tightly together while you turn your lights on. If the gauges are brighter than before, the rheostat's your problem. If they aren't brighter than before, your problem is either poor grounds or it's just the normal (bad) illumination.
If you determine your rheostat and grounds are OK, you can improve illumination by replacing the stock 3W bulbs with 5W bulbs.
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.