Installing Rallye Dash in a '74 duster issues

70dustah said
The search feature is your friend on this!! There is a thread on here about the ammeter to voltmeter conversion on rallye dashes, MAD electrical upgrade, removal of voltage limiter from fuel gauge and installing a solid state external one. DO your homework, do it once, and be done for 40 more years. I also refaced my odometer, had my gauges recalibrated ( redfish ) , replaced all bulbs and sockets, removed and polished lenses with a headlight polishing kit( the one with the powerball worked great) stripped and repainted bezel along with a decal from DMT. Can't stress it enough, search, search, and search more. All of the info is on here from some of our great members.

I also did the ammeter to voltmeter conversion. I used the guts out of a sun voltmeter gage, and the ammeter gage face and pointer. I cut the volt gage pointer off and glued on the original ammeter pointer. I was able to adjust the potentiometer on the new volt gage with its lighter ammeter pointer needle.

If you go this route, you will have to grind off a spot on your rallye gage housing so the bottom half of the gage doesnt hit and allows full swing of the gage. This is shown shaded in red in pic#3. I also added in a 12V led discharge light because i am running a denso mini alternator, and there is a spot in the back to wire in a discharge/fault light.

How i wired the gage in, is where the positive leg of the gage comes through the back of the housing , i enlarged that hole for a plastic grommet, and some plastic washers to insulate it. On the back side i ran a wire from the 12V+ stud of the gage , and jumpered it to the 12V+ feed lug coming into the cluster at the 12V+ feed going into the fuel gage.

The negative stud off the volt gage i cleaned the gage housing to bare metal so it would ground to the housing.

(Remember the gage housing is negative ground to the dash frame )