WOW am I confused! I though that truck was a '90 Fred?? Ain't no ballast resistor in that!
I've got a good electrical related story for ya this Christmas Eve ...
Twas the night before.. ..... .. ahem ... wrong story ....... SOOOOO ... I'm headed down Rt.20, that *censored* road that runs through that *censored* city called Worcester in my '72 El Camino with a buddy of mine. We had just left the bone yard with some parts I needed for something - way too long ago, so can't remember what ... but that's not important so forget I said that ... ANYWAY, it was raining, but summer time - so it was still 80° out, but with 99% TROPICAL humidity that combined with the heat pouring into the cab from the engine was making me sweat like a whore in church, and foggin' up the glass. So I cranked up the A/C AND the heat at the same time (had aftermarket under-dash A/C unit) to de-fog the windshield. I also had the wipers going ... AND headlights on ..... then BAM - no engine, no lights, no radio, no power ......
Then, my buddy yells YOUR ON FIRE!!!! Right between my legs was a giant fire that started from the ammeter wiring that got so hot, it shorted out on the gauge itself! So I pull over, no power steering or brakes because the engine is dead ... barely get stopped before I had flames coming up my chest .... dove out the door ... popped hood open, and ripped out my quick disconnect key on the ground cable (installed in Phoenix to keep thieves from getting away) ... then ran back to the cab and began furiously blowing on the fire. It actually went out!!
What a cloud of smoke!!
Luckily my buddy was one of those rich guys with a cell phone (circa '01), so he had his brother in law bring me the necessary wire and tools to bypass the under-dash gauge. On the road again.
Last time I ever used an ammeter too ...