by JimmieD » Wed Sep 25, 2013 7:57 am
I have 'fixed' a few of the older 60's & 70's headlight switches, doubt the newer ones are any different design? On the older switches: you pull out the knob all the way and press in on a button on bottom of switch to pull knob and shaft out of switch body. Sometimes have to fight it a bit to get it to cooperate! Then loosen chrome nut and spin it off so you can shove switch body through and out the back side of dashboard mounting.
You can then access the guts of the switch by removing multi-wire connector and gently bending some fold-over tabs on switch body and prying loose the fiberboard cover. Various types of specialty electrical contact cleaners, or a piece of fine emery paper or fine file plus contact cleaner to wash it out may be used to clean contacts.
The dash lights are controlled by a rheostat which is a wound wire coil that wraps around in a circle at back or front end of switch, with a wiper arm controlled by switch knob and shaft. Twist knob left for brighter lights, right for dimmer lights. This rotates the wiper arm around on the wire coil, allowing more or less voltage to be transmitted through rheostat coil and wiring to dash lights.
I've cleaned the rheostat coil and wiper arm for better conductivity, again with fine emery paper and spray electrical contact cleaner. Also the wiper arm may have lost spring tension somewhat and it's sometimes possible to give a gentle bend with a small needle nose pliers or hemostat etc. You're wanting to make the arm press harder on the wire coil. Most of this is pretty obvious when you get in there to take a look.
On the side of switch where fiber board cover is, the wires connect with a single large plastic or rubber connector to indivdual connectors sticking out of switch. May be necessary to use whatever tools you can to tighten the grip of that plastic multi-wire connector's individual female terminals onto switch's male spade terminals, again obvious when you look at it.
The dash light bulbs themselves are a push/twist plastic bulb body. Sometimes these can loosen or the contacts can be bent or dirty. Cleaning or replacement works there.
1967 Dodge D-100 Town Wagon - CPL 858 4BT, HTT Stage II/H1C 16cm/56cm turbo, '93 CTD I/C, 32K spring, minor fuel tweaks, milled head, NV4500, 1 ton springs, '72 D-200 Frt. axle w/ Air Lift bags, 4.10 Dana 60HD, F/R swaybars, Tom Woods shaft.
'90 W-350 gasser...
