Fuel Gauge needle pointing south no matter what

[Chris_Von_Bron]

Another new recent problem, my fuel gauge is pointing down no matter what.
So far I've done the following:-

I've used the multi-meter to verify that the signal from the green/black wire (for the gauge needle) beeps at the plug for the sender as it does on corresponding pin (A4) on the big white connector behind the binnacle. I then kept the multi-meter on the same sender end of the harness and tested each other pin of the binnacle connector expecting to hear another beep from another wire to indicate a short, but there were no other beeps.

I then performed the same test for the light green and orange wire (for the sender light) in the same way to the above, only to find the same outcome.

I'm pleased that there appears to be no short but stumped as to why my gauge is all of a sudden pointing south. The other gauges are all still running perfectly.

Any input or suggestions would be most welcome.

Thanks in advance

Chris

[Bitsyncmaster]

My car had intermittent fuel gauge and it would point strait down but I have the Zilla sender unit. It turned out to be a bad connection at the sender. So you may not be looking for a short but an open. Maybe your sender has an open circuit.

[David T]

My car had intermittent fuel gauge and it would point strait down but I have the Zilla sender unit. It turned out to be a bad connection at the sender. So you may not be looking for a short but an open. Maybe your sender has an open circuit.

Another possible place for an "open" is the flex PCB in the binnacle. That said, the sending unit has a very high failure rate. My Tankzilla was acting up so I pulled it and cleaned the wire in it. The stuff they call gasoline is VERY corrosive with even only 10% Ethanol and the steel wire corroded and was not making good contact with the wiper contact.

[Jonathan]

The open circuit failures I have seen on the fuel gauge always seem to leave the needle pointing straight up. If yours is pointing straight down, perhaps it is something other than the typical open circuit type problem?

Maybe you could dig into the area above the fuel tank and carefully remove the fuel sender for an inspection? If the float inside the sender is stuck down or something similar, it might do what you're seeing.

Also, could you post a picture of the needle on the gauge to show where it is pointing? Is it straight down or is it off to more like 5 o'clock, showing very low? Does the low fuel light come on while the needle on the gauge is pointing down?

[mburshtain]

My original fuel sender created a similar issue. After replacing it was stuck and I had to tap on the binnacle to release it.
After I replaced the sender this never happen again.

[DMC-Ron]

My car does this every now and then, particularly when the fuel tank gets low. When it first happened I called the previous owner and asked if he had seen this. "Yep, it's a common issue, just fill the tank and "bump" the binnacle. I was surprised to find it worked! He claimed there was a fix where a small peg is added to prevent the gauge needle from going too far south. I don't know if this is on the level, but a firm bump does "unstick" the gas needle. Of course repeated bumping of the binnacle over time is probably not a good thing so I'm wondering if anyone else has added a mechanical stop to the gas gauge for this issue?

Ron

[dn010]

One of the best things I've ever done for my D was to remove the cluster and then drill and insert little pins to keep the gauge needles from swinging out of range and getting stuck. Before that I had to constantly beat the hell out of the binnacle to get them to respond-not anymore. As stated it can also be that the sender is bad. Or, like for me, my gauge stopped responding so I replaced my DMCH sender with another DMCH sender only to have a non-working gauge still. It turned out to be a bad ground connection in the front wiring harness.

[DMC-Ron]

One of the best things I've ever done for my D was to remove the cluster and then drill and insert little pins to keep the gauge needles from swinging out of range and getting stuck. Before that I had to constantly beat the hell out of the binnacle to get them to respond-not anymore. As stated it can also be that the sender is bad. Or, like for me, my gauge stopped responding so I replaced my DMCH sender with another DMCH sender only to have a non-working gauge still. It turned out to be a bad ground connection in the front wiring harness.

Dan,
OK, good to know. Do you recall what you used for pins? Would you have a close-up photo of the fuel gauge?

Thanks for the help.
Ron

[dn010]

I don’t recall what I used, maybe I cut down a paper clip. I did this 16 years ago.

https://uploads.tapatalk-cdn.com/20180327/00b5b01243a34949d0061ff96b4c9e35.jpg


Sent from my iPhone using Tapatalk

[DMC-Ron]

I don’t recall what I used, maybe I cut down a paper clip. I did this 16 years ago.

https://uploads.tapatalk-cdn.com/20180327/00b5b01243a34949d0061ff96b4c9e35.jpg


Sent from my iPhone using Tapatalk

Thanks for the response and the photo. This is very helpful.
Ron

[dn010]

FYI, I’ve only installed pins on Fuel, Oil and Temp gauges. The rest do not need it.


Thanks for the response and the photo. This is very helpful.
Ron




Sent from my iPhone using Tapatalk

[Chris_Von_Bron]

https://lh3.googleusercontent.com/hMLyimoqodSVVjy6xLXj0a6QnAtoxhFhMz5GgQ7mnE3RNTjCRg Mt2NQOhIGaKe0qE6WJ5MXhMFbHaCfXbKrfqsjEGCAXXeYP6ZpJ bIUtnnqULaaw-yXRIv-_Armp51Fuhp7jI19BY1qG8jUAZ5TG6h6lspxHrE0a06yNbqOR7 2tx7e2ot0jjUXDRQbWIth459WhBNQxCxUXmm0kBUJG2hGTxKFO oXhq5ddt5_F9uYBV65EzIsbTUELVGO9IJQyPgfHPZ_TB7B2rvN hR5HKqhYuV14PNS1PXXCpmiZAxs1EbL1WRoVW6Bclz2clogqGJ ovaAvldKvAGAZhj9X-ss8pOgkl6ry9rJ9spwVjpLUtDwA5aXI459APBOjZUXsWMaO7u4 DSh4eWn270wbtCsZKqPtUwgtOUHb3ldvyrdENJRSYX0Z-909pri-fY7JPf6UZkDCDEoN6hBu2ZK-aVRSo_a1luoIiWMbzcw_DYTGrRh3PGjUttX58g2OKQR8mr9ISO b7WecYd2W9nJfmlqfM-_r1fWz8qpy5CV0bzXTj24KuEGg65fOu9WOm6iEs_kFe1S8QDw0 wSdJfQgB4XdlUpcPrv9t23UBbEE5ntcZI=w200 (https://youtu.be/SpuDcRCupf0)

Through the testing (as per the video I've just uploaded via the thumbnail above) I was able to confirm the issue wasn't the wiring or sender....

I hope this helps anyone else in the same scenario!

[mike123]

Just adding another instance of a needle pointing dead south (6:00) and a few light raps on the binnacle got it moving again.