Ok. . .So i replaced the fuel sending unit in my 72 dart with a spectre F69A. Even though it was not the exact dimensions of the unit i took out, i thought it might work because all the parts vendors say this is the correct unit for this car. Now, the gauge will read full when the tank is full, great. And reads empty after only using about 6 gallons, not so great. My question is, does anyone know which unit this dart uses? Was there a mid year change or something? The closest match we can find looks like a unit from a challenger, but that mounts through the side. Any ideas?
72 dart fuel sending unit
- Thread starter Dr. Dave
- Start date
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67Dart273
Well-Known Member
It seems to be a very sad fact that these repop senders are woefully inaccurate. I don't have the money, time, ambition or facilities to do testing on these. I wish I lived in a bigger area, with more of you guys around, I'd be glad to help work these out
First thing to do is make sure the instrument regulator and gauges are actually accurate.
To do that, go to Radio shack, and buy a combination of resistors that will give you about 10, about 25, and about 73 ohms. Don't use 1/4 watt, you probably want in parallel to give you at least a watt. Example, the 23-25 ohm, you can buy a package of 4 x 100 ohm, 1/2 watt, and wire all 4 in parallel. This gives you a resistor of 25 ohms, 2 watts
Buy a bag of clip leads, and cut three in half, solder the pigtail clips to your three resistor combos.
Now you can check BOTH the temp and fuel gauges.
Low/ empty, 1/2, and full/ hot. Leave the key on, and resistor connected for about a minute to let the gauge stabilize
If this checks out, You need to establish "empty" in the tank. This of cours may involve carrying around a (safe) can of gas in the trunk
Run the car out of gas, then add what you want for "reserve", say, a gallon
Now without moving the car, on the level, get into the tail lamp left kick panel connector, and separate. Take your ohmeter and carefully measure the resistance of the fuel sender at that point, whatever it might be.
This measured resistance is going to show you "where" the sender is
Now remove the sender, when you can, and lay it out so that (vise, etc) you can measure the float position. Hook up your meter and move the float until you duplicate your earlier measurement. THIS IS where the float would be in the tank with your 1 gallon (whatever) reserve.
Now devise a way (wood blocks, whatever) to mark the float location.
NOW bend the float arm until with the float in the earlier physical position, you get 73--75 ohms reading instead of your earlier reading. This SHOULD now put the float in such a position that when you have your desired reserve, the gauge will read close to MT.
"Full" might be another matter!!!!
First thing to do is make sure the instrument regulator and gauges are actually accurate.
To do that, go to Radio shack, and buy a combination of resistors that will give you about 10, about 25, and about 73 ohms. Don't use 1/4 watt, you probably want in parallel to give you at least a watt. Example, the 23-25 ohm, you can buy a package of 4 x 100 ohm, 1/2 watt, and wire all 4 in parallel. This gives you a resistor of 25 ohms, 2 watts
Buy a bag of clip leads, and cut three in half, solder the pigtail clips to your three resistor combos.
Now you can check BOTH the temp and fuel gauges.
Low/ empty, 1/2, and full/ hot. Leave the key on, and resistor connected for about a minute to let the gauge stabilize
If this checks out, You need to establish "empty" in the tank. This of cours may involve carrying around a (safe) can of gas in the trunk
Run the car out of gas, then add what you want for "reserve", say, a gallon
Now without moving the car, on the level, get into the tail lamp left kick panel connector, and separate. Take your ohmeter and carefully measure the resistance of the fuel sender at that point, whatever it might be.
This measured resistance is going to show you "where" the sender is
Now remove the sender, when you can, and lay it out so that (vise, etc) you can measure the float position. Hook up your meter and move the float until you duplicate your earlier measurement. THIS IS where the float would be in the tank with your 1 gallon (whatever) reserve.
Now devise a way (wood blocks, whatever) to mark the float location.
NOW bend the float arm until with the float in the earlier physical position, you get 73--75 ohms reading instead of your earlier reading. This SHOULD now put the float in such a position that when you have your desired reserve, the gauge will read close to MT.
"Full" might be another matter!!!!
Thanks, i ll try to do the resistance checks like you explained. My big concern, i guess is this. If the float is low after using 6 gallons, will the fuel pickup run out of reach at 7 gallons, or approximately 1/2 a tank, essentially running out of gas with 1/2 a tank left. Guess i ll have to carry a gas can until i figure out where empty is, like you said. Thanks again.
Woods74
Broke Senior
I had to adjust mine in this same fashion, I pulled the tank, filled it with water, made some marks, and bent it accordingly. Trial and error.
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