96 gti gauges

[snozeberriestastelike]

Hi everybody new guy here. I recently picked up a 96 gti. Did everything imaginable to get this thing running. New top end ,new crank, clean carbs replaced seals, gaskets, plugs,etc. Now that I have it running I'm fixing the small details. Right now I curious about the gauges specifically the fuel/info gauge. Other than corrosion what/why do these gauges not work? The original gauge was shot. Bought a decent looking used one that also didn't work. So as a tinkerer I cut it apart. The boards look good with minimal amount of corrosion that I hit with some electrical cleaner a brush. I check power were I could. But yet it doesn't work. Well I bought a second even better looking used one and it too doesn't work. The skis wiring all checks out as well. I would like to figure this out without buying a ton of non working gauges if possible.

 

[mikidymac]

Are you sure it isn't the sending unit. Typically that is what goes bad, the F1 fuse.

 

[snozeberriestastelike]

Are you sure it isn't the sending unit. Typically that is what goes bad, the F1 fuse.

Would that cause the gauge to not operate at all like no lights or shimmer when plugged in on the ski. I tried my best at bench testing by hooking 12v + up to purple wire and red/purple wire then ground to black. Nothing happens but when I hooked the ground up to the tan/blue line and took it of the main plug ground the LEDs would flash repeatedly which leads to believe the gauge is not fully dead.

 

[mikidymac]

I don't have the diagram for your ski but, Purple is power black is ground. Pink and Pink/Black are the signal for the fuel gauge. Do not put power to the Pink or pink/black as those should only measure resistance.
Blue would be the low oil light.

 

[snozeberriestastelike]

I don't have the diagram for your ski but, Purple is power black is ground. Pink and Pink/Black are the signal for the fuel gauge. Do not put power to the Pink or pink/black as those should only measure resistance.
Blue would be the low oil light.

Purple= power
Black = ground
Red/purple = comes off 5 amp fuse from mpem
Tan/ blue = goes back to mpem but also ties in with the buzzer which works and heat sensor not sure if it works. The wire to the temp sensor is good cause the buzzer goes off when grounded.
The r/p and t/b wires are on their own plug.
While the purple and black lines are on the plug with the pink/pink&black and blue/blue black.

One diagram I saw said that the red and purple wire send power to the gauges along with the purple wire.

 

[snozeberriestastelike]