Do I have a bad fuel sending unit?

[64stpside]

Now that I got my truck running right tonight, I decided to take on my fuel gauge issue. I put a new gas tank and sending unit in. I didn't put much gas in after I installed everything. I thought all was good because the gauge went to 1/4 tank. I put 5 more gallons in this week because I was going to try to take another test drive. Well, the gauge didn't move. If I remove the ground at the sending unit, the gauge pegs to full, with it connected it stays at 1/4. When the key is off, the needle drops....slowly. I took the sending unit out and moved the float and the gauge still says at 1/4. Did I get a bad sending unit or is the power wire grounding between the gauge and sending unit? I did see a post about the resistor on the gauge being a possible culprit. I decided to turn the key forward and reach up under the dash and start wiggling wires to set if that changed any thing, it didn't but when I touched the resistor on the back of the gauge, it was hot. I got a mirror to check the resistor and it's still intact but I'm not sure how to check it.

[gabbin]

I'd like to know what you find out, Im in a similar situation, my gauge will go to 3/4, but running it always stays on full. I've ohm checked the sending unit and it moves on ohms check and the gauge is new and wired accordingly. With the ground for the unit and again at the gauge. Im wondering what the heck the problem is. I was wondering if it only needed the ground back at the tank. Mine is moved to the back frame rails

[64stpside]

Today I used a neat piece of gear from work. It generates a signal to the gauge and you sweep a ohm knob (0-100) to check the gage . My gauge sweep was successful (0-30). Then I ran a wire from the fuse box straight to the sending unit to rule out a grounding power wire....no change. Then I pulled the sending unit and ohm tested it. The readings were all over the place. But I had readings. Then I hooked up the sending unit out of the tank and re-checked it.....same results. I think I have a bad sending unit. I'm taking the sending unit to work (I work at a chevrolet dealer) and get it checked again. I'll keep you updated.

[rudy62]

I had a similar situation. The original gauge uses 0-30 ohms. If you go digital, it has other ohm requirements. My issue was I ordered an under bed tank and thought I would change out my gauges. So I ordered for the digital requirements. Just can't remember the ohms now. Also, check out grounding.

[64stpside]

Originally Posted by gabbin

I'd like to know what you find out

My sending unit is bad. The tech here at work opened it up and started checking the ohms from the inside right off the the coil that the tab rides on and found a break.Sucks as I installed it, put 5 gallons of gas in last dec. and have been doing other things to get it road worthy and amp just now figuring out it's bad. Got it from eckler's. The next one will get tested right out of the box.

[gabbin]

Great idea, let me know what part# you getI need one as well. TY

[64stpside]

Originally Posted by gabbin

Great idea, let me know what part# you getI need one as well. TY

This is the one I got :
http://www.ecklerstrucks.com/chevy-t...1960-1966.html

[gabbin]

Perfect thanks for posting, that is exactly the same as I need. You rock!