69 d100 fuel and temp gauge

[Gelavive]

so I have a 1969 d100 Frankenstein (d100 frame/body/engine with w200 drivetrain) that I have been working on for years. I am almost done and trying to get the fuel and temp gauges working. I know both gauges along with both sensors work (tested with a little twelve volt drill battery) however, the wiring seems to prevent both from working off of the truck's battery. I have a wiring diagram but some extra help from someone who has had the same problem (or just knows how to fix this) would be greatly appreciated.

[Hobcobble]

so I have a 1969 d100 Frankenstein (d100 frame/body/engine with w200 drivetrain) that I have been working on for years. I am almost done and trying to get the fuel and temp gauges working. I know both gauges along with both sensors work (tested with a little twelve volt drill battery) however, the wiring seems to prevent both from working off of the truck's battery. I have a wiring diagram but some extra help from someone who has had the same problem (or just knows how to fix this) would be greatly appreciated.

Have you checked the Voltage Limiter? When it goes.... so do the fuel
and temperature gauge.

John

[Gelavive]

where might I find the voltage limiter on the truck?

[Hobcobble]

where might I find the voltage limiter on the truck?

I'm not positive on '69 and later gauge clusters. Look at the
back of the fuel gauge. Look for something like this.....

https://www.ebay.com/p/NOS-Mopar-1969-1 ... 2166364518

John

[dodgeboykim]

69 to 71 gauges are exactly the same mechanically as the 68 and earlier except for front markings. Lines or no lines.
Voltage limiter is built into the fuel gauge.

[DodgeBeast]

My knowledge is mainly in British cars but I do have a 69 Power Wagon now. The British cars are infamous for wiring issues. The fuel and temperature gauge are fed voltage from the ignition switch when you turn the switch on. The voltage is fed to each gauge and then to their respective sending units. The first thing to do is turn on the ignition switch (take the wire off of the positive side of the coil if you are going to have the switch on for a long time), take the wire off of the oil pressure sending unit and ground it. The gauge should move to the high side. If it does not move, you have no voltage going to the gauges. If it does move you have a bad sending unit. Repeat for the fuel gauge.

[PwrWgnDrvr]

....If it does not move, you have no voltage going to the gauges......

Maybe.
Or:
There is voltage at the gauge, but the gauge itself could be bad, or the wire from the gauge to the sending unit could be open.

[coelcanth]

Have you checked the Voltage Limiter? When it goes.... so do the fuel
and temperature gauge.

John

when the limiter goes bad do the gauges die or do they stay pegged ?

[Truckintom]

The limiter controls the input voltage to the gauges,I have seen them when they go bad or burn out ,they will create an open circuit,as in no voltage going into the gauge cluster, the dropped down voltage going in and thru each gauge operates the gauges by each sending units amount of ground,(fuel gauge example- full tank of gas,the sending unit supplies full ground to the gauge,this makes gauge needle go all the way to full), if all or one gauge pegs all the way as soon as you turn key on- good chance of a grounding problem in wirring,or bad sending unit,if you unplug the sending unit,then turn key on and that gauge does not peg,bingo,bad sender. Hope this helps.