Fuel Gauge wacky

[LannyL81]

Fuel gauge did work until removing interior, now it starys on the full side and needle bounces around alot. Seems like it has lost the ground connection, but connections are tight as all other gauges are working fine.

Is there someplace or something that others have found that causes this? confused

Thanks,
Lanny
St. Louis car
Tucson, AZ

 

[LannyL81]

Update on my wacky fuel gauge:

Is not an electrical problem (?) as going down the road, if I swerve the car back and forth, the fuel gauge needle does the same thing.

Turning the key to START, buries the needle past the full mark. And with the engine running, the needle bounces around, but stays near the full mark.

Gauge seems to read correctly with the key OFF; like it is getting power all the time. :confused

Cleaned the ground connection at the rear for the fuel sender.

Instrument ground must be okay as the voltage gauge works fine and according to the manual uses the same ground connection.

Checked connections on the back of the fuel gauge, seem to be tight. Took out the glovebox liner and could only do it by feel.

Could the low fuel mini circuit board be causing this???

Thanks,
Lanny
St. Louis car
Tucson, AZ

 

[tazdevl35]

Wacky Fuel Gage

I used to see a lot of this when I worked at Chevrolet as a tech and what i would do is remove the sender wires and insert a 90 ohm resistor in place of the tank unit and drive it around to try to reproduce the problem.If it doesnt do it problems in the tank unit (not at all uncommon in a GM product) if it still does it connect the resistor as close to the cluster where the sender wires connect as possible. This will isolate the harness and sender from the gage and low fuel board. If it still does it I would pull the cluster and inspect all connections on the connector and the P/C board for an open/short condition. Use a DVOM not just a visual inspection and the "wiggle test" to try to isolate the problem.Let us know what you find.


Taz

 

[LannyL81]

Update:
I pulled the fuel sender connections at the tank and thought I found the problem in a very corroded ground connection. After cleaning that, I put various resistors values between 40 and 90 ohms to the fuel gauge leads and the with the key ON the gauge showed different levels of fuel; just like it is supposed to do. I measured the resistance across the fuel sender and it was around 90 ohms.

So I guess the problem is in the fuel sender in the tank. Not sure what the problem is, but looks like I need to pull it out and take a look at it.

Are new replacements available??

Thanks,
Lanny

 

[tazdevl35]

Yes, mid america has them part # 613-001 price 169.99. You can order from 1-800-500-Vett or online at www.madvet.com. I'm glad you found the problem.



Taz