Hi everyone my 65 cutlass fuel guage quit working, It seems to be stuck at 1/2 when it ran out of gas .I checked it by first taking wire off of sending unit and grounding it. checked guage with key on still stuck at 1/2 . Checked again by adding another ground to sender. No change. Makes no difference what I do this guage isn’t moving. What do I do next?

 

Check for power at the gauge.

 

Ok I will check there. What about the wire to the sender? should it have power?
Can I check the ohms at the sender to try and determine how much gas I have?
All help much appreciated, thanks

 

The wire from the sender provides various levels of ground through the sender resistor to the gauge, the gauge has full battery voltage. The fuel sender is 0-90 ohms, 0 ohms =E and 90 ohms =F.

 

To check the guage for power would that be the 2 studs that go through the circuit board? Also is 0-90 ohms correct for 65 sending unit? I saw 0-30 ohms on some other post regarding sending unit. Can I check the sending unit ohms with the wire off? thanks again.

 

To the best of my knowledge the 30 ohm sender was through the 64 model year. 90 ohms was 65 and up.

 

Ok then 0-90 ohms. Can I check the sender with the wire off?
On the guage do I check for power at posts on the back?
please advise

 

Yes and yes

 

Cannot detect any power at the guage so I’m at a point that I don’t know what to do. The fuses all have power on both sides
the sending unit seems to at 24-27 ohms right now. Any more ideas?
thanks

 

I tested for ground at the guage it was good on one post so I ran a jump wire from fuse box to the other post then took a look at the guage, it went from 1/2 to E . At least it moved. I’m going to put some gas in and see if it’s working again.
will let you know........

 

Put in $30 gas no change on guage, came home and connected jump wire from fuse box to guage again, turn on key
guage goes to a little over half. I’m at the conclusion my sender is good but the guage isn’t getting power from the circuit board. If I just connect a wire to the post it should fix the guage to working condition again. Thanks for the advice

 

Does your parking brake, gen, oil pressure, temp lights work?

 

This car has no light for the brake. I have Stewart Warner oil and temp gauges so no sensors on motor. Gen light I took out the bulb because it was annoying me and the charging system is working but couldn’t figure out why light stays on.
but that’s another story.

 

The sender gets its power from the same fuse as the idiot lights. You may have messed up the wiring when you put your gauges in or disabled the gen light.

 

The wire color is green/white and goes to pin 2 of the printed circuit connector.

 

Gauges don’t have any wires not even lights, all I did was remove gen light bulb. Didn’t think that had anything to do with fuel guage, but I can put the bulb back and see. All fuses are good.

 

Not saying the bulb itself has anything to do with it, I was saying basically its an old car and if you disturb things in an area it may create bad connections. Also if your fuse block has corroded fuse mounting tabs you may very well have voltage on both sides of the fuse but not on the load side tab itself. Sometimes cleaning or simply removing and reinstalling the fuse will fix that. I've provided as much info to you as I can, your going to have to find where you lost power to the gauge. Once you restore power you can simply remove the wire at the sender with the key on and the gauge needle will go past F. If you ground that wire it will drive the gauge needle to E. If it does this then all of the gauge wiring and the gauge is operating correctly.

 

Yeah it is 54 years old, I’ve already cleaned all the fuse connections, the circuit board isn’t the greatest 1 post is loose and I think one is missing but I had traced it down to hi beam light when I had the dash apart. The fuel guage was about the only thing that did work when I got this car . I didn’t disturb the circuit board other than cleaning. I’m thinking the circuit board is bad. Thank you so much for your help. I can usually figure things out for myself but I’m a mechanic machinist and not strong on electrical stuff especially things like this that usually don’t go wrong .

 

65 cutlass fuel guage quit working no power at guage , bad circuit board?
Run a wire to it ? not sure how to fix this any suggestions?
thanks

 

There was no reason to start a fresh thread on this as there had been troubleshooting history to your issue. Yes, run a power jumper to the fuel gauge and run a chassis ground also.