Join Date: Mar 2002
Location: Austin, TX, USA
The tail and dash lights may be fed from the same power circuit, I'm not sure, but they have seperate fuses. Your loosing power as heat somewhere in a bad connection. Check the guage fuse (small fuse at the bottom I believe). Measure voltage between the end of the fuse and it's respective clip on both ends. You should see 0.01 or less drop with the lights on. Fuse clips are notorious for corrosion in which case I'd expect you see a volt or two being dropped accross the bad connection. You may also find that the fuse clips are warm to the touch. You can use this same voltage drop test throughout the circuit to find where the bad connection is. Don't overlook the bulb sockets themselves. They have brass tabs on them that will corrode and the copper foil they ride against will tarnish. Take a little scotch-brite or 400 grit sandpaper to scuff them up and dope them with dielectric grease before installing them again. The grease will minimize the chances of it happening again and make the bulbs go in easier. 30 years of corrosion will make those bulbs stick hard enough to make you worry taking them out. Feels like they will break in your hand. Once greased they'll work like new again and may fix your dimness problem. Do the same with the instrument panel connector - scuff the tabs and the foil traces the contact. Then dope them with the dialectric grease.
68 Coupe, 350 w/ Edelbrock Performer RPM heads, cam, intake, 700R4, Dave's small body HEI