Thanks chengny for bearing with me and trying to help.
I have put all new after market gauges in and have taken out the printed circuit.
1. The old gas gauge was hit or miss but that and the speedometer were the only gauges in the cluster when I bought the truck.
2. I’ve got all 8000 series gauges from Equus.
3 & 4. I didn’t get the tank switching figured out till after I had removed the previous gauge. The problem ended up being the switch. Both tanks now function and switch properly.
5. There was no tach in the original.
6 & 7. I’m referring to the male plug in the dash. Each side is numbered: 1-9, then 10-18. Pin 18 is the pink wire, that I think lines up with pnk30.
9. I’m not sure about the splice point.
10. If VOM means Volt Ohm meter, then yes. If not, then I’m not sure what that is.
Other questions:
1. I did figure out how to utilize the fuse box. I wasn’t sure if I could wire it through the box or if I would have to splice into a wire on the headlight circuit.
2. I did also figure out how to tie into the fuse box for the ignition.
So I now have a working tach, volt meter, temp gauge, and oil pressure. I was hoping I could tap into some of the wires on the mail plug to connect to the new fuel gauge. Is that possible? What wires came together on the printed circuit to make the factory gauge work?
Thanks again!
Shane
Just like the engine coolant temperature and oil pressure gauges, the gas gauge requires that three leads be connected to it:
1. A 12 VDC power supply, and
2. A direct path to ground, and
3. A sensing leg - with a variable resistance to ground (that is dependent on the media being monitored)
I am confident that if you were able to gut your original cluster, cobble together a new one with aftermarket components and get everything working (except the gas gauge), you have correctly wired the gas gauge's power and direct ground leads.
That leaves the sensing leg as the most likely cause - that the GG doesn't indicate the correct tank level.
The sensing leg is comprised of 3 basic components:
1. A power supply into the sender (the PNK 30 lead) from the gauge
2. A wire wound variable resistor controlled by a float in the tank
3. A lead out of the sender - that connects directly to ground (a short blue or black wire that bolts to the frame)
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Things get more involved when a tank transfer valve is included in the circuit, but for the sake of simplicity we'll ignore it for this part of the discussion.
Anyway, to diagnose this condition, start with the easy stuff.
1. Make sure the sender's ground connection is securely fastened to the frame - and that there is no paint or rust between the terminal and frame. Also check the other end (i.e where it connects to the sender).
If that ground seems to be okay, move on. You can check for continuity with your meter to be sure. One probe on the sender connection and the other probe to the frame (near the actual terminal). You should read full continuity or get a beep.
2. Next check is the PNK 30 lead. Find the splice point. It is under the cab at the back LH wall (you'll see where it exits the rear lighting harness loom):
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Key in RUN, break the snap button connector and verify 12 VDC. If confirmed, ground the PNK 30 to the frame (the part that runs forward to the firewall). Key still in RUN - the gauge should peg to "E". Isolate the PNK 30 from ground and the gauge should now peg to "F".
Start with those tests and see what you find out.
