Instrument cluster fixes/upgrades?

[Backally]

70 Duster, rallye dash. I was having some lighting issues so pulled the instrument cluster out. I believe I had some bad grounds, cleaned them up and tested using a 12v motorcycle battery and it appears they are now good. But while it is out, I am going to inspect and upgrade some things so I hopefully never have to pull it out again. Once thing is upgrading the IVR from mechanical to solid state. Think that is a should do since it’s out.

I am really on the fence about converting the ammeter to voltmeter. I have done Crackbacks headlight relay kit and also his Alt-batt cable. I have disassembled and cleaned the bulkhead connection and feel that is pretty solid. I do have efi, the display shows volts at the battery so I do monitor them. The benefit I see by getting rid of the ammeter is eliminating all the power going through it, if it malfunctions things shut down. But with Crackbacks upgrades is that something I still should be worried about? On 50yr old wiring? Did I just answer my own question??

I will be sitting down today going over the wiring diagram to find a key on 12v source if I go voltmeter. I do have a wire for an electric choke being unused I could thread through, can’t remember exactly what it comes off of but would that work? I believe that is key on only. How many amps does a voltmeter draw? I would think minimal.

Since I got this cluster out, is there any thing else I should inspect? Right now only other real issue is the trip odometer hangs up, so speedometer will be opened up probably.

 

[67Dart273]

You don't need to add anything for a voltmeter. There is already switched 12V at the cluster--what feeds the IVR for the gauges.



What to do?

There's been about a thousand posts on this subject, so do a search

Check your PC board harness connector pins for loose, and solder the loose pins

Check the contact fingers for the IVR and solder jumpers across to the board traces

Loosen/ tighten the gauge nuts to scrub the PC board / deoxide/ and remake the stud terminals

If you don't have a solid state IVR get one

Clean the PC board traces where the bulb sockets contact with an eraser, clean the socket contacts or replace and replace the bulbs / LEDs

ADD a grounding pigtail to a ground point on the board, and bolt that to the column support/ dash frame

 

[Backally]

You don't need to add anything for a voltmeter. There is already switched 12V at the cluster--what feeds the IVR for the gauges.

OK, I get it. I did look at a couple posts about putting in a solid state IVR, it just didn't click that it gets power from the same source. I was thinking you are adding something, you need to add a power connection.

I did check the other things you suggested. Pins are all tight, I had added the additional ground previously. I will loosen/tighten the gauge nuts, that makes sense.

Is there anywhere to find a diagram of the rallye dash? I have found one for a Barracuda in my manual, but it doesn't seem the same as my Duster. I looked on Mymopars and all they got is Challenger

Thanks, appreciate the help!

 

[67Dart273]

You don't need a diagram, just follow the traces on the board. A diagram does not exist unless someone made one. The factory diagram shows what harness pins goes where from the harness side.

I did not think / realize you have a Ralleye dash. On those the IVR is built into the fuel gauge. If yours is working, great. If you have to replace it, you will have to disable the one internally and piggyback one to the outside.

If you can post a good clear shot (or two overlapping) of the rear and front of your cluster, we can tell you were things are and what they do.

You need a wiring diagram/ service manual for the car, if not dowload one free at MyMopar