Instrument cluster voltage limiter.

The ammeter is not connected to the temp / fuel gauge. The IVR supplies power to both the temp and fuel gauges. There are several places for problems here

1.....The harness connector and the pins loose at the pc board. You must repair them. My board was so bad I abandoned the original connector and soldered pigtails to the PC board traces, brought them out, and hooked up "Molex" style connectors to replace them

2....The IVR itself, and the socket it fits into. On my 67, the brass contacts were not making contact between the contacts themselves and the board traces.

http://www.forabodiesonly.com/mopar/attachment.php?attachmentid=1714669336&stc=1&d=1383154832[img]

Consider buying a solid state RTE unit. There are projects on the www where you can construct a 5V regulator yourself to replace it

3....The gauge unit studs / nuts. They may not be making reliable contact with the PC board.

4....The guage units may not be accurate, or have something wrong, or even have debri, or "bugs" (insects) etc inside. You can check the calibration with resistors in substitute for the senders. The gauge units are identical so the resistors for checking are the same

The resistances are

L = 73.7 Ohms (empty)
M = 23.0 Ohms (1/2)
H = 10.2 Ohms (full)

For example, you can go to Radio Shack and buy four 100 ohm, 1/2 watt resistors, and wire all four in parallel. This gives you one 25 ohm resistor. Put this in substitute for the temp or fuel sender to ground, and leave the key in "run" for about one minute. If the system is working and accurate, the gauge should read 1/2 scale. (middle.)

5.....Grounding. Grounding is originally poor. Hook additional ground pigtail to the cluster, and bring it out and bolt to something such as the column support

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So far as the ammeter, I would inspect it for mechanical damage. These are a complete POS design. They are essentially held together by "luck" They are a piece of brass with two studs, and you may have "moved things" when you disconnected / reconnected the two wires. You may have knocked the needle off the pins

There's not much in there...........I don't know what model this one is (off the www) but it's just a needle on two simple pivots

[img]http://www.bradsnosparts.com/yahoo%20pics/120408%20001b.jpg