Testing gauges with new voltage limiter
Understanding these circuit boards is about as simple as getting the rabbit to the Trix on the back of a cereal box. All 3 of the thermal gauges have a post in a common copper trace. That is the 5 volt trace. The gauges each have another post in a trace. That is the sender side of the gauge. Only remaining question is the 3 post fuel gauge. which is sender and which is 12 volt? I'll answer that question. The pin at 12 o'clock/top center of round connector is the sender trace to the fuel gauge. You already see where 5 volts is on the fuel gauge. The only remaining post has to be the 12 volt into the limiter. You can follow that trace back to the pin at about 9 o'clock position of round connector. There you have it.
The printed circuit boards on rally panel never changed (other than blue or green color). With the instrument panel on the workbench and the wiring harness is in the car, factory wire casing colors are irrelevant.
Understanding these circuit boards is about as simple as getting the rabbit to the Trix on the back of a cereal box. All 3 of the thermal gauges have a post in a common copper trace. That is the 5 volt trace. The gauges each have another post in a trace. That is the sender side of the gauge. Only remaining question is the 3 post fuel gauge. which is sender and which is 12 volt? I'll answer that question. The pin at 12 o'clock/top center of round connector is the sender trace to the fuel gauge. You already see where 5 volts is on the fuel gauge. The only remaining post has to be the 12 volt into the limiter. You can follow that trace back to the pin at about 9 o'clock position of round connector. There you have it.