Okay so I have two *wiring* questions:
1.) I FINALLY got the elusive silver faced tachometer cluster for my ‘78 LS swapped Pontiac. I swapped the tach with my clock setup and changed the “clips” on the circuit tape to match the tach cluster I removed the tach from. Soldered a jumper for V8. Went to splice the tach wire from my LS PCM into the stock harness and I don’t have a pin on the dash plug with the factory “white” tach wire. Figured, okay. I traced the three clips on the cluster for the tach back to the plug leads. I found the ground, found the pink power, and what I believe to be the “signal” pin because it leads to nothing on the dash plug. So I soldered the LS PCM tach lead to that pin, fastened it down, turned the car over and got nothing. Any thoughts? I’ve read on here that if your car came with the dummy light cluster (mines original clock and dummy cluster) you will NOT have the white tach wire pin in your dash plug. That checks out because the upper left two pins are non existent and the one clip leads to on of the empty pin slots. I’m curious as to what I can do? I figured running my tach signal directly to the clip would bypass even needing to add a pin to the dash plug but that obviously didn’t work either. Everything else works though, all my rallye gauges work and the speedo works with no issues.
2.) Also, I purchased a third brake light. My car being a ‘78, which wire should I tap into just for the brake lights? When I go look at the brake switch, I only have two wires, an orange and a blue. I read a bunch of mumbo jumbo about having to swap a bunch of stuff, to get JUST the brake lights to turn on and not the turn signals. Is it true? I’ve read about the logic box but can’t seem to find one (probably searching for it with the wrong name). And yes, the third brake light does work, I bench tested it. Would I be able to buy a later year brake switch from a vehicle with the third brake light? Or will that mess up things since I’ve also read that the brake switch wiring is then picked up by the turn signal/hazard wiring?
Thank you all! I’m stumped and I’m usually quite good at figuring this kind of stuff out. The Facebook groups have left me with no responses as of now. After a few hours of troubleshooting and diagram researching, I found nothing conclusive.
1.) I FINALLY got the elusive silver faced tachometer cluster for my ‘78 LS swapped Pontiac. I swapped the tach with my clock setup and changed the “clips” on the circuit tape to match the tach cluster I removed the tach from. Soldered a jumper for V8. Went to splice the tach wire from my LS PCM into the stock harness and I don’t have a pin on the dash plug with the factory “white” tach wire. Figured, okay. I traced the three clips on the cluster for the tach back to the plug leads. I found the ground, found the pink power, and what I believe to be the “signal” pin because it leads to nothing on the dash plug. So I soldered the LS PCM tach lead to that pin, fastened it down, turned the car over and got nothing. Any thoughts? I’ve read on here that if your car came with the dummy light cluster (mines original clock and dummy cluster) you will NOT have the white tach wire pin in your dash plug. That checks out because the upper left two pins are non existent and the one clip leads to on of the empty pin slots. I’m curious as to what I can do? I figured running my tach signal directly to the clip would bypass even needing to add a pin to the dash plug but that obviously didn’t work either. Everything else works though, all my rallye gauges work and the speedo works with no issues.
2.) Also, I purchased a third brake light. My car being a ‘78, which wire should I tap into just for the brake lights? When I go look at the brake switch, I only have two wires, an orange and a blue. I read a bunch of mumbo jumbo about having to swap a bunch of stuff, to get JUST the brake lights to turn on and not the turn signals. Is it true? I’ve read about the logic box but can’t seem to find one (probably searching for it with the wrong name). And yes, the third brake light does work, I bench tested it. Would I be able to buy a later year brake switch from a vehicle with the third brake light? Or will that mess up things since I’ve also read that the brake switch wiring is then picked up by the turn signal/hazard wiring?
Thank you all! I’m stumped and I’m usually quite good at figuring this kind of stuff out. The Facebook groups have left me with no responses as of now. After a few hours of troubleshooting and diagram researching, I found nothing conclusive.
