Fuel Sender Resistances

[legacybt]

I've recently installed a V1 Radium fuel hanger and now my fuel gauge reads empty, but sweeps on key on.  I'm moving through troubleshooting what's gone wrong and am hoping for some assistance from some of you knowledgeable people!  There is a bunch of custom wiring done so I'm in for a bit of an adventure, but the circuit should match stock. 

I've tested the following points.  

1,5 = 61.5 Ohms (BIU to ground, both senders in series)

2,5 = 61 Ohms (Local harness to ground, both senders in series)

2,3 = 19 Ohms (Driver side sender plus some harness)

3,4 = 42 Ohms (Passenger side sender plus some harness)

4,5 = 0 Ohms (harness ground to chassis)

I also shorted the passenger sender connector so I had 42 Ohms between the BIU and ground, but still no reading at the gauge. 

 

Next steps = install a 20 Ohm resistor between points 2 and 4 to bypass all of my new wiring and see if the gauge reads. 

 

I'm hoping to get answers for a few questions:

- are the resistances I'm measuring in spec for expected fuel sender values that should read non-zero at the gauge? 

- Any other ideas for what the culprit might be? 

- If there are iffy connections anywhere, could you expect the BIU to read something different than the multimeter? 

 

Thanks!

[legacybt]

Ok, I hooked a 10 ohm resistor up across the circuit so simulate what should be a pretty full tank.  Still nothing.  
 

Does anyone know what the voltage between points 1 and 5 in the diagram in my last post should be while the gauge is reading?  I measured 1V and I don’t know if the BIU should be monitoring at a higher voltage (5V?) - I’m thinking something might have been damaged in there. 

Edited October 21, 2023 by legacybt

[legacybt]

Resolved by attempting to start the car… looks like everything was hooked up right, it just needs an attempted start cycle in the ECU/BIU to display fuel level instead of only key on.