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Faulty fuel tank sending unit

Old 04-09-2019, 05:53 PM
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Default Faulty fuel tank sending unit

Inherited a 01 Park Avenue (base) and the fuel gauge wasn't working properly from the get-go. Anytime a scanner was hooked up there was a code indication of a bad fuel tank sending unit. After it left me walking time or two, I got a replacement from Rock Auto and installed it. The original sending unit looked bad, with the little "fingers" on the contacts corroded and broken. The new one DID NOT work any better than the old one. The fuel gauge will show almost full and in a minute or two less than a half tank. Often, the needle will show 3/4 (or more) full and when I park for a few minutes and restart, the needle will be on empty and the low fuel alarm sounds. Do I have a wiring problem or a just a crummy replacement part?
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Old 04-09-2019, 06:58 PM
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maybe a bad step motor ( fuel gauge motor)
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Old 04-09-2019, 08:34 PM
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I have a rheostat that I disconnect the wiring to the pump and apply the rheostat to the sending circuit and see it the gauge responds correctly. If so that eliminates all the wiring. The only thing left is the connector and the new sender. You can get a simple rheostat and do this. It'* worth it.
BTW rheostat and potentiometer are the same.
https://www.mouser.com/Passive-Compo...eostat&FS=True
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Old 04-09-2019, 09:01 PM
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You can get a rheostat, or the correct set of resistance values....40 ohms is E, 240 ohms is F, 90 ohms is 1/4, 140 ohms is 1/2, 190 ohms is 3/4.....
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Old 04-15-2019, 07:39 PM
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OK, I got an assortment of resistors and pulled up trunk carpet and fuel pump cover. The wiring harness that connects the sending unit has three wires, tan?, green and black. Which two do I jump with the resistor?
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Old 04-15-2019, 08:34 PM
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Should be two connectors on fuel module........one for pressure sensor, 3 wires....one for pump and sender, 4 wires......

You want the 4 wire connector.......attach resistor to A and D terminals......Term A is purple, and terminal D is black with white tracer....
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Old 04-15-2019, 09:33 PM
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I located the correct plug and wires and installed a 91 ohm resistor first. The gas gauge needle initially stopped on the 1/4 tank mark, but after a few seconds moved slowly to the 5/8 mark and stayed there. The second resistor was a 150 ohm and the needle flipped all the way over past the full mark. I have a pack of 200 ohm resistors, but didn’t try one of those because I figured the gauge would only indicate full.

Is this little test indicative of a bad fuel gauge?
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Old 04-15-2019, 09:59 PM
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If those resistors are the correct ohms of 90 and 150, should have been 1/4, and slightly over 1/2.....

There are several connections before you get to the cluster......the only way to verify, is disconnect the cluster....leave the 150 ohm resistor attached, and then take a resistance reading at B17 and B7 of the cluster harness...if you read 150 ohms, it'* the cluster......
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Old 04-16-2019, 07:02 PM
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Originally Posted by bluiewest1 View Post
I located the correct plug and wires and installed a 91 ohm resistor first. The gas gauge needle initially stopped on the 1/4 tank mark, but after a few seconds moved slowly to the 5/8 mark and stayed there. The second resistor was a 150 ohm and the needle flipped all the way over past the full mark. I have a pack of 200 ohm resistors, but didnít try one of those because I figured the gauge would only indicate full.

Is this little test indicative of a bad fuel gauge?
Yes. Typical symptoms are no fuel gauge, gauge jumps(older models) or dying fuel pump.

Now is the time to change out the sending unit.
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Old 04-17-2019, 08:53 AM
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bluiewest1 Curious, I assume that you got a new pump complete with sending unit? What brand did you purchase ??
There is some very good information in this thread.

My 97 PA is also starting to act up as well. At around 6/8 of the tank, the needle starts doing the dance up & down, luckily no low fuel alerts.
If & when I have to replace the whole pump assembly, I would probably buy a Carter assembly, as it'* a bit of a hassle to replace them & I only want to do this once.
I knew there was a sock for fuel filtration, does anyone know on our pumps, if they also have media filtration built in the casing itself as well?
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