slow day at work and read appox 94 threads on gauge issues. my 74 challenger with rallye gauges, speedo ng, odometer works, need speedo. check.gas gauge goes to 3/4 maybe float or ground. check. tac ng but p.o. installed electronic ignition so a easy fix i think.clock ng. who cares .just kidding.so oil, amp and h20 gauges ng.but the p.o. installed after market oil and amp gauges which work.why he did not do a h2o gauge, good question.so if i replace the original oil, amp gauges , can i use the wiring from the aftermarket stuff to the refurbished stock units.seems logical but logic and old cars sometime do not mix. long post for a short ( no pun intended) question.
Translated as best I can:
Speedo = Odometer functional, Speed indicator nonfunctional. Proposed solution: Replace entire speedo.
Gas Gauge = Full tank reads 3/4. Proposed solution: Check ground/Replace float
Tachometer = Non functional. Previous owner installed electronic ignition (74's came with this standard).
Clock = Non functional. Not an issue
Oil pressure = Non-functional. After market installed. Proposed solution use aftermarket wiring with original.
Amp Meter = Non-Functional. After market installed. Proposed solution use aftermarket wiring with original.
Temperature = Non-Functional.
For the Temperature gauge, I would first make sure the car has a thermostat installed. It is not unusual that these have been removed. I recommend a Stant 185* if it's missing. Make sure you drill a small hole in it. Next I'd check the sending unit for potential issues.
Clock you'll either need to get a conversion kit to quartz, buy a rebuilt/NOS one. I don't think the electromechanical originals are serviceable.