1994 Sundancer grounding points for gauges

[94SD370]

One of my fuel gauges acts like a windshield wiper and the other doesn’t work at all. Someone suggested this is a common grounding problem. I have the dash apart for another project, so before I put it all back together I would like to clean up the terminals and see if that fixes anything. I cannot tell where the wires ultimately go to. Obviously, they end up at the fuel tank sending units, but I do not know where they tie into a grounding point. If I knew where that point is, I can clean those leads too. Any all all suggestions are welcome. Thank you in advance.

 

[Lazy Daze]

Run a temporary, known-good ground to see if that makes it better. If it does - then start hunting - or just run a permanent, new ground.

Pull the sender out and manually check it.

 

[ttmott]

The "ground" on the fuel gauges is the wire that goes to the sender on the fuel tank. Those should be a Pink wire and Pink/Black wire (port / starboard). There should be a black wire on the senders also that routes to the main DC ground buss.
The other wire on the fuel level gauge routes to the Ign/Start switches. That wire is Bat Positive and should be violet colored.

 

[94SD370]

The "ground" on the fuel gauges is the wire that goes to the sender on the fuel tank. Those should be a Pink wire and Pink/Black wire (port / starboard). There should be a black wire on the senders also that routes to the main DC ground buss.
The other wire on the fuel level gauge routes to the Ign/Start switches. That wire is Bat Positive and should be violet colored.

I have brown, blue and violet and pink. The pink is solid on both the port and starboard on mine. Blue (I believe) is for the light bulb. My “brown” must be your black? Thank you, this is my project today!

 

[Lazy Daze]

Pink - sender wire
Blue - Light bulb
Purple - Switched +12V
Brown - Ground

 

[94SD370]

Pink - sender wire
Blue - Light bulb
Purple - Switched +12V
Brown - Ground

Thank you. I ran a jumper to the pink wire and the gauge pegged to the full side. Perhaps I should run that to the brown wire? On the tank itself, I could not find the sender as the tank is mostly slid in under the non removable floor. It has pull hooks welded on, so I suppose the only way to get to that is to remove the waste water tank, pumps and plumbing. Then slide it out? I really do not want to go down that road. The only accessible thing is the fuel line itself entering the top of the tank, but there are no wires connected to it (that I can see).

 

[scoflaw]

the grounding point would be the ground wire on the gauge.

 

[Lazy Daze]

Yes, my suggestion above was to run a known-good ground to the ground on the gauge as that was what we where talking about (grounding). If the gauge then acts normal, simply run a new, pemanent ground to the gauge.

FYI, there may be a ground bus bar somewhere behind the dash - if so, that is where the gauges would get their ground. BUT... are the grounds all daisy chained? If so, the only bad connection would the short ground for the fuel gauges... otherwise all gauges would be dead.

Explore getting to the senders again as this is, by far, the most common problem with fuel gauges. There should be either a removable pie plate or the floor above the tank, itself, may be removable with screws.

 

[ttmott]

The wire from the fuel level sender to the gauge isn't a "ground", it is a battery negative bias. Don't apply battery positive to that wire as the sender instrument in the fuel tank will be destroyed.