99 Mustang v6

The gas gauge will show anywhere from empty to half a tank at random, one start up may be half, next start up might be empty, even with the tank is full. Currently i am probably somewhere around 3/4 of a tank and it is showing empty.

I have checked OHMs coming out of the connector back by the tank, 93 ohms, i checked for it at the main dash harness behind drivers kick panel and it had 92 ohms, followed it up into the cluster and was 89 ohms.

But even with the ohms pointing to about 1/2 of a tank, when i put the cluster back in after ohming it out, i should have seen the gauge around 1/2, but it was barely at 1/8th of a tank.

I can do the cluster diagnostic and the gauge does a full sweep from empty to full back to empty on the initial start up, so i know the gauge works.

I have checked all the solder points on the back of the cluster where the main ribbon comes it, checked the 4 contacts around the gauge itself and did not see anything abnormal.

any ideas or thoughts?

 

the sender card in the tank is the most common cause, the strategy of the cluster is to display the key on fuel sender reading, and to buffer the sender while its running to prevent erratic gauge needle movements due to slosh. so you will notice very little movement of the needle with a bad sender unless you shut the ignition off and then on again.

 

I understand that, but technically if I am getting the ohms for half a tank coming into the cluster, when I put key on it should reflect that correct?

The 3 spots I checked ohms at were at different times, and car was at different levels.

1st at the back was car lifted on jack stands under the rear end

2nd was at the kick panel connector with the car off jack stands

3rd time when I checked the cluster I turned the car around and put in the garage, so at a different slope than previous 2 readings.

All 3 were consistent and should have been around 1/2 tank, yet all back together it shows empty.

Still leaning towards bad sending unit? Or possible something in the cluster