If a rally dash cluster, draw a clocking line on the back of the gas gage face to the gage housing so you can line it up putting it back together. Usingg a miniature set of wire cutters (dykes) carefully pry the crimps holding the gage face to the housing and remove the face. You will be staring at pic #1 carefully dewire the points regulator inside the gas gage and leave the 12V feed stud intact on the back and make a solid state IVR. Will cost about $7 in electronics store parts. That 12V feed stud provides a 12V feed to the new external IVR and a 12V feed to your volt gage.
Also no light will bleed thru the cut out. I put aluminum tape over the hole to keep dust out. I also used flexible and dimmable 5630 LED light strip to line the gage housing. You could replace the illumination bulbs with hi bright LEDs and get the same or similar look. The strip light is peel n stick, and I ran the wires to a bulb socket. Available at evilbay in many colors. Super inexpensive.Typically about $6-$8 per 5 meters lol. That's like 13 feet.
The ammeter bypass is more than just connecting the 2 wires together. However the rest of that mod is done at the engine side of the firewall since it bypasses alternator output to the battery and (bypasses the bulkhead connector). Last pic is the bypass. One above it is unbypassed.
Take your circuit boards and solder the wiring harness pins pins to the copper tracings on the board, then take small brass brads, cut them short to fit down inside the circuit board pins allowing the pin head to overlap the back of the pin where its crimped. Either JB weld them in or solder them in to prevent to pin from loosening and pulling out.
This should just about fix everything that's fucked about the rallye dash cluster.
Hope this helps
Matt
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