fuel and temp gauge reading jumping around

[Jim Blaschke]

My fuel and temp gauges are acting inconsistely. I pulled out the cluster and found that someone at some point put a ground wire coming off the thumb screws of both gauges and grounded them to a metal point behind the cluster. How are these gauges typically grounded? Does the metal cluster glass ring have any ground function? Yes the other body grounds have been cleaned and checked. Any insight would help. Thanks 1971 model year 2002.

[SteveJ]

You are on the right track. The extra ground wires usually solve these issues. I installed mine with star washers to help bite in and make the ground. 

 

Clean everything. Maybe run the instrument ground wire off to its own body connection, rather than through the harness/connector.

 

Also, check connections at the senders.

Edited June 12, 2018 by SteveJ

[PaulTWinterton]

What worked for me:

 

Underneath the regulator is a major (brown) ground wire.  The sheet metal screw goes into the fender.  Both the screw and fender (hole) need to be cleaned down to bare metal.  I replaced that screw with a through-bolt.  My fuel gauge stopped fluctuating randomly after that.

 

There are a number of ground points on the car.  Best to clean all of them for better performance from gauges, signal lights, etc.

[Buckeye]

You may want to clean two ground wires connectors at the base fuel and coolant temp gauges in addition to extra ground wires to thumb screws and ground wire under neath the regulator. That was remedy to my coolant temp gage fluctuation in recent week.

 

 

[larryt]

i have the same problem! my fuel gauge is acting up big time. since re-assembling the car, the fuel gauge wasnt working at all, so i switched the wires on the sender and the gauge jumped to the top. this assures me that there is some power there. 

 

now

 

when i run my stereo the gauge actually moves in time with the music, as cool as this looks (down with the kids flashing lights/moving things etc..) i would much rather it serve its function as a fuel gauge! any ideas?

[jrhone]

Running the extra ground wires to the gauges solved  my problem. Make sure those grounds are good.  

[larryt]

1 minute ago, jrhone said:

Running the extra ground wires to the gauges solved  my problem. Make sure those grounds are good.  

 

i will have a dig about and re-wire and get back to you with an update!  thanks 

[Kuntacharlie]

I replaced the ground wire from the battery negative terminal to the body with a heavy gage wire. That solved most of the problem I was having with the temp gage needle ticking up and down in time with the turn signals.

[larryt]

19 hours ago, Kuntacharlie said:

I replaced the ground wire from the battery negative terminal to the body with a heavy gage wire. That solved most of the problem I was having with the temp gage needle ticking up and down in time with the turn signals.

 

so this wire on mine is new, but i will double check