Digital Fuel gauge CS, New pump and send unit

[JanS1983]

My 1994 grand marquis had fuel gauge problem when i bought it.

Tested the old fuel sending unit and at full it was 199 ohm, so old one was definitely broken.

Ordered a new complete assembly from rockauto partnumber SP2122H.

Now i still have CS on the dash and the fuel gauge still not working.

When i finish it i filled the tank, at first it worked but not as it should, it started at 45 litres and slowly it got up to 60 / 70 litres, now it shows CS with the 2 bars top and bottom or it shows 0 and the fuel gauge is blinking.

Could it be that the fuel sending unit is for analog cluster?
or could it be just a bad one?


I cleaned the battery clamps and tested the battery and is good.

I know the fuel gauge on the cluster is good, when i turn the key to ignition it show the all the bars.

I tried to take the cluster out, to test the connection but couldn't get the light switch knob off. Any tips how to get the light switch knob off?

Thnx and greetings from the Netherlands

[friskyfrankie]

Could be a short or corrosion in the connector at the fuel tank that feeds the gauge. I have the same possible issue but just haven't gotten to it to test the theory.

[JanS1983]

friskyfrankie oke i going to take a look at that.
Mine says CS (circuit short)

Could it be the inertia cutoff switch? Car is starting and running fine though

[massacre]

I used to use a small hook made from a piece of coat hanger to remove the headlight knob. If you think it's a circuit short i'd be checking for that.

[friskyfrankie]

friskyfrankie oke i going to take a look at that.
Mine says CS (circuit short)

Could it be the inertia cutoff switch? Car is starting and running fine though

Inertia switch would have nothing to do with the "CS" issue. That switch only cuts the fuel pump, electrically from continuing to pump in the event of an impact, especially a rear one.

[massacre]

IIRC, the sender should also have a ground connection to the fuel pump hanger flange. That ground is part of the 4-pin connector to the fuel pump (black wire)
Maybe check continuity of both the sender wire and sender ground?

[JanS1983]

Last weekend i got the cluster out of the dash, with a magnifying glass i inspected the soldering points and there where some bad soldering.

With a soldering gun i tried to fix the bad soldering, at first it worked for 2 days haha. And now it says CS on the dash, i know now that the cluster is bad.

What is needed to change the digital cluster to a analog one?

[sly]

The pinout for both. Connectors for both. They are different. You'll be rewiring both connectors. Also, if you get an analog cluster from that year range (92-94), you will need to replace the plastic gears in the speedometer. They are known to shatter. Also, I don't know what year went to a single coolant temperature sensor using only the engine computer sensor to drive the gauge cluster, but you'll need something older than that. I know for sure that is at least 2000 or older. But I would expect it to be 92-94 mainly.

here's the pinouts for 1994.

[JanS1983]

Some probably will hate me for this .
The cluster is bad, and finding a cluster that is in perfect and working condition here in Europe is zero, the gauge works between 0 -- 190 ohm.

It is reversible when i find a working cluster.

[Arquemann]

That is a very clean installation.

Since it seems the cluster soldering is faulty, could you send the cluster to a electronics / cluster repair shop? I've had a Alfa Romeo cluster resoldered here in Finland, it was like 100€.