1994 s10 fuel guage problem

[jrwhitey_2000]

I recently purchased a 1994 s10 with a 2.2l automatic. The gas gauge reads empty when the key is turned on, but will read when the power is off. I lowered the tank down far enough so that I could unhook the ground wire. The guage on the dash goes to full with the ground unhooked, but goes back to empty with the ground connected. I dropped the tank completely out and then pulled out the sending unit and fuel pump. I ohmed out the sending unit per the haynes manual and I go the following readings. The power plug has 2 wires and then I have 2 wires that go to the same connector at ground on the frame. When I check the continuity from one of the power wires to ground and move the float I see no change in the resistance so I assume this is the fuel pump power wire. I check the other power wire and ground and it reads a little less than 2 ohms empty and it reads over 92 ohms full which the book says is correct. What is my problem. I do not mind spending money to purchase the correct part, however I do not want to replace something that is not bad. I got a good deal on the truck. $175.00. The owner said it had a broken vrank however I found out as soon as I went to look at it that the center of the flexplate was busted out. I fixed the flexplate and the motor and tranny work perfect. Please Help.

[MT-2500]

Originally Posted by jrwhitey_2000

I recently purchased a 1994 s10 with a 2.2l automatic. The gas gauge reads empty when the key is turned on, but will read when the power is off. I lowered the tank down far enough so that I could unhook the ground wire. The guage on the dash goes to full with the ground unhooked, but goes back to empty with the ground connected. I dropped the tank completely out and then pulled out the sending unit and fuel pump. I ohmed out the sending unit per the haynes manual and I go the following readings. The power plug has 2 wires and then I have 2 wires that go to the same connector at ground on the frame. When I check the continuity from one of the power wires to ground and move the float I see no change in the resistance so I assume this is the fuel pump power wire. I check the other power wire and ground and it reads a little less than 2 ohms empty and it reads over 92 ohms full which the book says is correct. What is my problem. I do not mind spending money to purchase the correct part, however I do not want to replace something that is not bad. I got a good deal on the truck. $175.00. The owner said it had a broken vrank however I found out as soon as I went to look at it that the center of the flexplate was busted out. I fixed the flexplate and the motor and tranny work perfect. Please Help.

Check the hot wire going to gauge with a old fashon bulb test light.

It should ligh up dim with key on and move gas gauge.

Ohm on tank sending unit hot/ground should move when raising or lowering float.

[jrwhitey_2000]

As far as the ohm readings, they are reading what the manual says they should be. Are you saying to take a bulb test light and connect the alligator clip to ground and then plug the other end into the connector. With the key on the guage should move and light should be dim?

[MT-2500]

Originally Posted by jrwhitey_2000

As far as the ohm readings, they are reading what the manual says they should be. Are you saying to take a bulb test light and connect the alligator clip to ground and then plug the other end into the connector. With the key on the guage should move and light should be dim?

Hook the test light to the wire from fuel gauge to tank.