Electrical 5.0 Resto Gauge Cluster Fuel Ohms

Hello everyone, been a while but I’ve been doing a lot of work on my 89 GT and I finally got around to installing the 5.0 Resto “Factory inspired” Dakota digital cluster.

Everything works pretty god despite the fact that the fuel gauge isn’t accurate. I just recently installed a brand new fuel sending unit and fuel tank harness in prep for the cluster. Lmr states that their sender outputs 145 ohms when full and 22 ohms when empty. Dakota digitals pre configured sender setting is 20-150.

They also give you a way to test to see how many ohms the control box is seeing and mine at a full tank is seeing 164 ohms. The fuel gage is pretty inaccurate due to this. The fuel gage won’t even move below full until it drops below 150 due to Dakota digitals pre configured ohm settings.

I’m using 18 gauge wire which is Dakota digitals recommended wire gauge. I spliced the fuel sender wire at the connector at first but the ohm was reading 167 at full and then I spliced at the kick panel and it dropped to the 164.

Besides doing the custom calibration that they offer, is there anything else I should check and look for? I’m running minimal wire lengths to the control box which is mounted behind the radio. I know Dakota digital says 10% is to be expected but if I go off of LMRs specs for the sender I’m out of my 10% range and if I go off of DD specs I’m just barely within 10% but still pretty inaccurate

qikgts said:

Have you removed the sender from the circuit and checked the output?

A band aid might be to put a 1.5k ohm resistor in parallel with the circuit. That should take the 167 ohms your seeing now to 150.27 ohms. It will however always effect the circuit.

Another thought is maybe the anti-slosh module is the issue here.

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I don’t think the Dakota digital box and cluster use an anti slosh module. I’m not exactly sure how it’s regulated other than ohms. The resistor could be a solution I’ll have to look into it I didn’t even think about that.

I haven’t checked the output of the sender yet that will be next on my list. I’m not sure if the factory wiring would cause that much extra resistance given that it’s in good shape so the sender is definitely suspect.

I also just checked the reviews on the LMR sending unit which is what I should’ve done to begin with but a lot of people are complaining about the exact same thing. After some testing if I can’t find anything glaringly obvious I’ll try to use Dakota digitals custom fuel sender calibration and make it work that way.