Most models of Panteras have a Reostat/Potentiometer that when rotated brightens and dims the 2 lights directly above the 'Center Console', you know the dash that holds the 4 main gauges. At the same time, it also controls the brightness of the Hazard switch, the wiper and the Washer switches. It does NOT control the Lighting on the 4 major gauges or the Speedo and Tach(the reostat for those is mounted under the dash, above the drivers left knee, at least on My '74, it is). The first mentioned Potentiometer is mounted straight across the top-most rocker switch from the Ampere Gauge. Now, to get to the point! I had changed the two 'White' lights at the top of the central dash to Red. A nice glow when seen at night that does not ruin your 'Night Vision'. I had changed over the fist bulb, and it worked great but when I installed the second, Nothing. No lights on, above the gauges nor the Hazard, wiper or washer switches. But all of the dash lights still worked. Looking at the wireing diagram and seeing that ALL of these combined lights work off of the same fuse #3; I deduced that the curcuit 'Break' had to be either between the 2 'Top Lights' and the reostat or just before the reostat, or the reostat itself. Getting out the trusty VOM and testing proved NO voltage at the 2 lamps. And Voltage was present AT the reostat input. Removeing the reostat is real simple, take out the drivers' kick panel at his right knee, unscrew the plastic bezel around the reostat (no need to remove the knob!) and pull the stat from behind the dash, it's easy, it's right at the edge. Pull it down, the wire has plenty of slack; and remove the two wires(Orange-12 Volts IN and Yellow/Black 'Controlled' OUT to the lights)) connected the the Male spade connectors. Polarity does not matter. (after marking an Index mark so as to get the back on in the same orientation), Take apart the Stats' Back side by prying up three thin metal tangs. Be careful as two and then two more small metal balls will fall out. No worries, they go back in very easy. Upon pulling the back off you will be greated with two identically 'spiral wound' resisters, side by side and mounted to the inside of the 'Back' you just pulled off. At one end are the two Male Spade connectors going through to the outside, at the other end will be a very, very small wire that is suppose to connect those two ends of the twin resiters together for continuity. You will find that wire, bearly seeable because it is as THIN as one Human Hair, believe or not! It will not be melted, it is simply Broken in half. It must have 'just' been able to carry the current of the 5 small light bulbs, and when I installed the two red lights, which were just a 'couple' more watts; the little 'Hair' went 'Plink'. Now the fix: The thin wire spanned a gap aprox. 1/4" Clean/scratch the brass sheet metal on either side of that gap, 'tin' it with a soldering iron, strip the insulation off of a piece of wire (I used 22 gauge), tin its' ends and solder it to bridge the gap. Be carefull to heat the brass for a little time as it takes to melt the solder on, for a good hold, as you don't want to damage the fine filiment of the Resisters. Two of the steel balls go back under the springs that are with-in the two plastic plungers, the plungers go back into their pockets; the last two balls go in their pockets ON TOP of the plungers. These balls cause the nice 'Click' detent that you feel when you rotate the stat. The other two balls push the brass ribbon contacts down, And ALONG the length of both spiral-wound resisters; the result a 'Veriable Resister' that we know as a 'Potentiometer' or 'Dimmer' to others. Carefully, being mindful not to lose the Balls, replace the backside into it's metal housing, aligning it with the index marks you previously scribed ( I did NOT find it neccessary to use grease to hold the balls in place, and you don't want grease in there anyway). With a small flat blade screwdriver bend the three tabs/tangs back into position, while puposefully holding the back in place against the spring pressure. Use needle-nose pliers to fully seat the tangs into their pockets. re-hook-up the two wires to their spades. Polarity is not important, if it is to you, then looking at the back with the spades at the top of the stat; the orange wire(s) go on the RIGHT spade with the Yellow/Black on the LEFT. If you have one, Use your VOM and check the resistence: Full on, it will read 39-40 OHMS (this stat is rated at 40) when turned to max. brightness I got 6-7 OHMS, you wont get Zero, probably from the instrument leads. Reinstall the reostat in reverse order of removal, tightening the bezel, and replace the kick panel. Try the lights now, Perfect!! Give yourself a 'pat on the back', and go get one of those Buttery Nipple things; and congratulate yourself on how much money you just saved, not having to hunt down and purchase one of these things. "I love it when a plan comes together!". Happy New Years!!! and Cheers!
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