Got a full tank of gas but digital fuel gauge reads empty with 0 miles to go. I got under car and unplugged the 2-wire connector on sending unit. Still read empty. I do have power at one of the wire harness terminals and the other terminal must be a good ground because I don't get a reading on my meter until I connect to that ground terminal. I think I was getting about 9 volts on the positive terminal. I don't know how to jump the sending unit to test the fuel gauge. I know if it was an analog gauge with a needle, I could just put a jumper wire between the 2 terminals and the gauge should go to full. I tried that but the digital gauge must be different. I checked the ohms between the 2 prongs of sending unit and it was bouncing around and couldn't get a good reading. Question- does anyone know how to perform the test to see if the digital gas gauge is operating correctly? Does the wire harness run directly from sending unit to back of fuel gauge? I read somewhere that that wire harness goes to the voltage regulator before going to gauge. I read the fuel sending unit for the digital gauge is impossible to locate. I might put a sending unit for an analog gauge and just install an aftermarket gauge in. That's why I need to where that fuel sending unit wire harness is. Has to be under dash somewhere. Thanks for any help.
89 Town Car digital fuel gauge
- Thread starter pete315
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michaelt62
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The electronic fuel gauge has it's voltage regulator built into the display and the sending unit is in the tank where you tested it. The only difference between the conventional gauge sending unit and the electronic gauge sending unit is that the resistance is reversed as described in the pic's below.
michaelt62
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michaelt62
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No problem, The shop manuals/electrical diagrams are a must have to make things simple. When testing the gauge, make sure to turn the ignition off when changing resistors, the gauge ignores resistance changes for a short time to allow for fuel slosh while driving. Since you indicated above that the resistance of the sender is erratic/bouncing around, that may be your problem. The variable resistor can be removed so you can check it for wear/worn spots, and you can check the flexible connector arm to make sure it maintains connection as it moves across the resistor.
michaelt62
MY Cars: https://www.youtube.com/channel/UC-Tv0kuDyQhbH-DrqF71zYQ/videos
Seems like there’s enough room to remove sender without lowering the tank. I may be wrong though. First to test the sender resistance with my new meter. I’m hoping not to get a reading around 211 ohms which would mean I have a problem with the gauge, not the sender.
I tested the resistance again with a new meter and got a reading of 7.2 ohms with a full tank of gas. Should have around 211 ohms. So, I have a bad fuel sending unit. Now the hunt for a fuel sending unit for the digital fuel gauge. Might have to search for used ones which will be a nightmare. I had an idea- if I install a fuel sending unit for the analog needle gauge which goes from 73 ohms full down to 10 ohms empty, I can install this in my car and when the float arm is going towards empty and the ohms are approaching 10, my digital fuel bars will be reading full with most digital bars illuminated because an empty tank with a digital sending unit is approximately 3 ohms. I'll just read the gauge backwards. As my gauge is approaching full, I know I need gas. Thoughts? I hate this type of fix but what else can I do.
oktowncar
Well-known member
Pull the sender and see if you can visibly see any defects. You might just have some luck and be able to fix the issue
I'm going to try that first. I'm hoping maybe the float got a hole in it and filled with gas causing it to fall to bottom of tank even though tank is full. I just got this 89 Cartier. My dad bought this Lincoln in 1990 from our neighbor who was a salesman at a local Lincoln dealership. It was a trade in that looked like the day it rolled off the assembly line. I think it had about 3,000 miles on it when he bought it. My dad always parked car in the garage. Never seen snow or salt covered roads. Barely saw any rain either. Then he sold it to my brother who kept car garaged and was never taken out in snow or ice also. Now I own it. Has 102K miles on it now. I just replaced the rear shocks because it was sagging in the rear a little. The rear shocks might have been the originals (the fronts were changed). The top nut of shock spun off like it was installed a week ago. Zero rust or corrosion. No salt roads and always garage are life savers on these older cars.
I got another used fuel sender for the digital dash. Gauge works now. You can remove sender without dropping tank. Plenty of room. Took longer to jack up car than to remove sender. I retested the old sender. Still only 5 ohms of resistance when float was in full tank position. I moved float up and down a couple of times and now I’m getting the correct resistance as float arm moves from full to empty. Maybe it was a dirty contact. The car did sit in garage not started for over a year. Either way, I have a spare fuel sender unit for the digital dash which is different from the analog gauge. If some needs one, let me know.
oktowncar
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gfvcammel
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do you have a part number for the correct sending unit?
G
G-348271
I bought a used fuel sender unit from a parts car. I pulled original sender out and the ohms remained the same as I moved the float rod. I cleaned the contacts on the sender and the ohms started to change as I moved the float rod. Guess contacts were dirty. I did hook up the used sender I bought and moved sender outside the tank and the gauge was moving as I moved the float rod. It’s for sale if you need the fuel sender for the digital dash. $150 plus shipping. That’s what I paid for it.
I do. The sticker was still on sender. E5VF-9275-AA. I bought a used one from a parts car. Works as it should. My friend knew I was looking for this sender and he told me about another Lincoln Town Car that was about to get junked. It had the digital dash, so I took out the sender. Removal of sender takes 3 minutes tops. Very simple. I unplugged my sender and plugged this spare sender in. As I moved float arm, the gauge was working. So, I know this sender works properly. I have since sold my Lincoln to a car collector. I have this spare fuel sender on Facebook Marketplace place right now for $150. That's what I paid for the first replacement sender. Let me know if you're interested.
LTC89BC
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I’m interested in buying that sending unit, do you still have it?
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