Powerman5K Posted March 6, 2023 Share Posted March 6, 2023 This past week, my fuel gauge started acting wonky and I figured I'd ask the Bullnose Brain Trust for answers. Today, I left for work with a full tank of gas. My gauge was reading half a tank. Within 2 miles, it went to nearly empty (where it stayed the rest of the 40 minute drive). After work, it read half a tank the entire ride home then as I turned on my street it shot up to full. I replaced the sender within the last year. Is there anything else it could be before I drop the tank (not my favorite thing to do), to swap out the sender again? Link to comment Share on other sites More sharing options...
Gary Lewis Posted March 6, 2023 Share Posted March 6, 2023 You will probably have to replace the sender as that's classic wonky-sender behavior. But you can test the gauge and all the wiring by pulling the wire off the sender and grounding it. The gauge should go to Full or higher, indicating that all but the sender is good. Link to comment Share on other sites More sharing options...
BigBrother-84 Posted March 7, 2023 Share Posted March 7, 2023 After work, it read half a tank the entire ride home then as I turned on my street it shot up to full. My dream! A Bullnose fuel tank that magically fills up while driving! Link to comment Share on other sites More sharing options...
mat in tn Posted March 7, 2023 Share Posted March 7, 2023 After work, it read half a tank the entire ride home then as I turned on my street it shot up to full. My dream! A Bullnose fuel tank that magically fills up while driving! amen Link to comment Share on other sites More sharing options...
mat in tn Posted March 7, 2023 Share Posted March 7, 2023 You will probably have to replace the sender as that's classic wonky-sender behavior. But you can test the gauge and all the wiring by pulling the wire off the sender and grounding it. The gauge should go to Full or higher, indicating that all but the sender is good. i have had even new replacements do this. double check all grounds first. one seemingly strange symptom is if it acts up more on very humid or rainy days. corrosion holds moisture and at times cam work better once dried out. clean the grounds first I have also found it helpful to add a ground strap to the tank. one with the barbed s clip and go to the frame nearest. please don't drill into the tank to run a bolt. this is more for the young guys reading along but hey we see some crazy stuff done to old trucks. Link to comment Share on other sites More sharing options...
81-F150-Explorer Posted March 7, 2023 Share Posted March 7, 2023 After work, it read half a tank the entire ride home then as I turned on my street it shot up to full. My dream! A Bullnose fuel tank that magically fills up while driving! Link to comment Share on other sites More sharing options...
Powerman5K Posted March 8, 2023 Author Share Posted March 8, 2023 i have had even new replacements do this. double check all grounds first. one seemingly strange symptom is if it acts up more on very humid or rainy days. corrosion holds moisture and at times cam work better once dried out. clean the grounds first I have also found it helpful to add a ground strap to the tank. one with the barbed s clip and go to the frame nearest. please don't drill into the tank to run a bolt. this is more for the young guys reading along but hey we see some crazy stuff done to old trucks. I'm going to test the grounds this weekend as Gary mentioned. Then go from there. If the sender is truly bad, I'm going to buy the best one money can buy to replace it! I hate dropping the tank! I just replaced it last May! Link to comment Share on other sites More sharing options...
Machspeed Posted March 8, 2023 Share Posted March 8, 2023 i have had even new replacements do this. double check all grounds first. one seemingly strange symptom is if it acts up more on very humid or rainy days. corrosion holds moisture and at times cam work better once dried out. clean the grounds first I have also found it helpful to add a ground strap to the tank. one with the barbed s clip and go to the frame nearest. please don't drill into the tank to run a bolt. this is more for the young guys reading along but hey we see some crazy stuff done to old trucks. I've been dealing with a dead fuel gauge for several years now. I put new sending units in the tanks about five years or so ago. Checked them out before I put the bed back on and they seemed to function. After putting the bed back on, noted they no longer worked.....ARGHHHH!!! Interestingly, my gauge seems to work in rainy weather. I'm sure it's some sort of a groud problem which I think requires dropping the tank or pulling the bed, niether of which I want to do. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted March 8, 2023 Share Posted March 8, 2023 i have had even new replacements do this. double check all grounds first. one seemingly strange symptom is if it acts up more on very humid or rainy days. corrosion holds moisture and at times cam work better once dried out. clean the grounds first I have also found it helpful to add a ground strap to the tank. one with the barbed s clip and go to the frame nearest. please don't drill into the tank to run a bolt. this is more for the young guys reading along but hey we see some crazy stuff done to old trucks. I've been dealing with a dead fuel gauge for several years now. I put new sending units in the tanks about five years or so ago. Checked them out before I put the bed back on and they seemed to function. After putting the bed back on, noted they no longer worked.....ARGHHHH!!! Interestingly, my gauge seems to work in rainy weather. I'm sure it's some sort of a groud problem which I think requires dropping the tank or pulling the bed, niether of which I want to do. John does your tank selector valve work? The senders ground at G701(the main ground near the radio) Both senders come together at Splice 154, which also takes the lights from the rear. And then join again at a major Splice (155) I'd think if either of these splices were bad you'd have other noticable issues. So if it's both senders that are out I'd think they are individually damaged, or it's the feed wire between the instrument cluster and selector that's gone wonky. Link to comment Share on other sites More sharing options...
Powerman5K Posted March 9, 2023 Author Share Posted March 9, 2023 You will probably have to replace the sender as that's classic wonky-sender behavior. But you can test the gauge and all the wiring by pulling the wire off the sender and grounding it. The gauge should go to Full or higher, indicating that all but the sender is good. Gary, can you describe this process a little more? I remove the positive and negative leads to the sender. Then run a ground to the frame. If the dash reads full, the sender is bad? I don't have to do anything to the power lead? Thanks! Link to comment Share on other sites More sharing options...
Recommended Posts