1996 Lincoln Town Car: replaced the fuel pump and now the gas gauge reads wrong and doesn't change levels or indicate the instrument levels. What went wrong?

Hi Ron,it's connected to your fuel pump as assembly,andit's located inside your fuel tank.Here's a pic. of it. http://www.autozone.com/external-engine/fuel-pump/spectra-premium-fuel-pump/lincoln/town-car/2000/8-cylinders-w-4-6l-sfi/161728_839486_0 Here's how to replace. Repair Guides Gasoline Fuel Injection Systems Fuel Pump AutoZone com Here's how to relieve your fuel pressure. http://www.autozone.com/repairinfo/repairguide/repairGuideContent.jsp?pageId=0996b43f802e6615 Here's how to remove your gas tank. http://www.autozone.com/repairinfo/repairguide/repairGuideContent.jsp?pageId=0996b43f802e65a8

Fuel pumps outside the gas tank have nothing to do with fuel gauge readings. There is a fuel level sender unit inside the tank with a float which supplys variable ground circuit to the gauge. If you can find the wire to this unit, you can ground it to see if the gauge now goes to full. If so, sender unit in tank is bad, or has bad wiring/ground.

Did you did any tune up,fuel filter,air filter,coils.

instrument cluster is just for monitoring. but on modern cars there can be integrated circuits to calculate the actual amount of fuel inside tank. so sender sends signals and dashboard decodes it and show the amount on gauge.

which car do you have? if it is a later model with such system you may need to reset related software to match with new sender unit on pump or floater. (dealer can do this for you)

for example if you have a new daylight driving lights(LKM) controller on new BMW's if you replace it with a new one you need to code it to match with your car. if not it wont operate correctly.,

But there is an exeption. when sockets are broken or connections are wrong, fuel and temp gauges act erratic. they jump, pulsate or dont work at all. before replacing anything more be sure that sender unit or whole asembly is the correct part for your car. second be sure that connection has been done correctly.

Hello
If it was a fuse problem none of the gauges would work or the warning lights. The problem is caused by a defective fuel gauge sending unit that is located of course inside the fuel tank. To rpelace this part requires the fuel tank be dropped out of the car.

P0460 Fuel Level Sensor A Circuit Malfunction, ford posted this service tip for all 97 to 05 ford vehicles - INTERMITTENT MIL ON WITH DTC P0460 - SERVICE TIP
SOME 1997-2005 VEHICLES MAY EXHIBIT AN INTERMITTENT MALFUNCTION INDICATOR LAMP (MIL) ON WITH DTC P0460 (FUEL LEVEL SENSOR CIRCUIT MALFUNCTION). THIS CONDITION MAY BE CAUSED BY AN IMPROPERLY INSTALLED REMOTE START SYSTEM, AFFECTING THE FLUID LEVEL INPUT (FLI) INFORMATION TO THE PCM. THE CONDITION MAY BE DIFFICULT TO DUPLICATE. TO SERVICE, CHECK FOR AN IMPROPERLY INSTALLED FORD OR AFTERMARKET REMOTE STARTER SYSTEM. THE INSTRUMENT CLUSTER OR HEC MUST HAVE POWER TO ALL 'HOT IN RUN' CIRCUITS FOR THE FUEL GAUGE CIRCUIT TO PROPERLY RELAY FLI INFORMATION TO THE PCM (EITHER BY NETWORK COMMUNICATION OR A DIRECT HARDWIRE CIRCUIT another I have seen addresses the fuel problem just says the tank got over filled, the gas cap is bad, and that the system is clogged due to a poor grade of fuel being used, Ford recommends a Chevron fuel cleaner additive that should improve this problem

1. Disconnect the negative battery cable.
2. Remove the instrument cluster.
3. Remove the retaining screws for the instrument cluster lens and cover assembly. Remove the cover and lens.
4. Remove the retaining screws for the gauge or warning lamp to be replaced and remove the gauge or warning lamp. To install:
   
5. Place the gauge or warning lamp into place and tighten the retaining screws.
6. Install the instrument cluster lens and cover assembly.
7. Install the instrument cluster.
8. Connect the negative battery cable.

The owner's manual addresses this problem. It tells you to take it to a dealer for repair. The problem is most likely the fuel gauge sending unit which is located in the fuel tank and is mounted just above the fuel pump. It is probably sticking at the level that it was at for so long. It can be replaced by raising the rear of the car and accessing the fuel pump and sending unit from under the car behind the rear axle. Disconnect the two fuel lines and unplug the wire harness and remove the lockring with a hammer and screwdriver. Lift and turn the fuel pump assembly out for inspection and/or replacement . THE FUEL TANK DOES NOT HAVE TO BE REMOVED. I have done this many times.

possiblity the float rod got bent on installation

This is a normal concern.
The instrument cluster uses 4 different operating modes to calculate the fuel level:
Anti-slosh (default mode)
Key OFF fueling
Key ON fueling
Recovery
After a fuel fill up, the time for the fuel gauge to move from empty (E) to full (F) ranges from 2 seconds to 55 minutes depending on which operating mode the fuel gauge is in.
The default fuel gauge mode is called the anti-slosh mode. To prevent fuel gauge changes from fuel slosh (gauge instability due to changes in fuel sender readings caused by fuel moving around in the tank), the fuel gauge takes approximately 55 minutes to go from empty (E) to full (F).
The key OFF fueling mode (2 seconds to read empty [E] to full [F]) requires 3 conditions be met:
The key must be in the OFF position throughout the entire refueling of the vehicle.
At least 15% of the vehicle's fuel capacity must be added to the fuel tank.
The instrument cluster must receive a valid key ON fuel sender reading within 1 second of the key being put into the RUN position. The key ON sample readings are considered valid if the fuel sender reading is between 15 ohms ± 2 ohms and 160 ohms ± 4 ohms.
If these conditions are not met, the fuel gauge stays in the anti-slosh mode, which results in a slow to read full (F) event.
The key ON fueling mode (approximately 90 seconds to read empty [E] to full [F]) requires 3 conditions be met:
The transmission is in PARK (P).
The key is in the RUN position.
At least 15% of the vehicle's fuel capacity must be added to the fuel tank.
In key ON fueling mode, a 30-second timer activates after the transmission is put into the PARK (P) position (automatic transmissions). When the 30-second time has elapsed and at least 15% of the vehicle's fuel capacity has been added, the fuel gauge response time is 90 seconds to read from empty (E) to full (F). When the transmission is shifted out of PARK (P), the fuel gauge strategy reverts to the anti-slosh mode. The key on refueling mode prevents slow to read full events from happening if the customer refuels the vehicle with the key in the RUN position.
Recovery mode is incorporated into the instrument cluster strategy to recover from a missing fuel level input during a refueling event. Missing fuel level inputs result from intermittent opens in the fuel sender or its circuits. Recovery mode (empty [E] to full [F] approximately 20 minutes) is initiated when the following 2 conditions are met:
The instrument cluster is in the anti-slosh (default) mode.
The actual fuel level in the tank is greater than what is being displayed by the fuel gauge