Rallye cluster gauge issues

Rallye cluster gauge issues - 67 Barracuda

RedFish said
I would think a tachs backlight would be connected to the orange wire/illumination circuit somewhere. Tach is accessory. These harnesses didn't include provisions for accessories. Thats why the factory tach package included a add on harness for it. I dont know how you or a previous owner are going about tapping wires or how you lost power to the limiter. Twist them together and tape them up doesn't always work. Could be a loose pin at circuit board too. Moving the wires about would move that pin. The only wires that depend on the pins are those to light bulbs. Every other wire could be attached directly on the corresponding post with a ring terminal, same as the wires on the amp gauge. Toothed washer and 10-32 hex nut on top of the speedy/PAL nut. E-body for example doesn't have a printed circuit board. all the wires are attached with 90 degree push on like the one on your noise cap'. Those owners have to know which color wire goes where.

Yes I checked for proper seating of all the pins and connectors. The previous owner had stripped a section of the insulation from the blue/white wire and twisted/taped the backlight feed to the old tach on to it. I simply soldered and shrink wrapped the same connection (but instead feeding +12V to the new tach, there is no separate backlight) when I installed the aftermarket tach. While there is no concrete evidence to back up my theory at this point (only circumstantial), it would appear that the faulty tach was disturbing the operation of the IVR inside the fuel gauge and causing all of the gauges in the cluster to behave erratically. The assumed path of the disturbance is the blue/white wire. Since removing the power feed to the faulty tach, gauge function appears to have returned to normal. I am taking no bets that the problem will not re-occur however. They could have been co-incidental events (the tach failure and the flaky gauges) caused by disturbing the 53 year old cluster in the first place to do the tach installation. I am planning to pull the cluster again to remove/return/replace the tach and overhaul the cluster with new PCBs, lamp sockets, and perhaps replacement gauges, although those are pricey and currently out-of-stock.