Gas Fuel gauge not working

[Doug Overkill]

I’ve got a 1997 Challenger 1800 and the gas gauge isn’t working. The low oil light does work. There is 12v coming into the gauge thru the purple wire as there should be. I’ve done all the diagnosis around the sending unit and the F1 fuse and all at the tank end are working as supposed to.

When power is applied to gauge the needle doesn’t move at all. Should ‘jump’ up a little to E once powered. With 12v on purple and ground to black - shorting across the pink and pink with black strip should show full. It doesn’t.

Everything I try and no motion on needle at all.
Anyone find a way to open these up and repair the gauge itself?

 

[2strokeboy]

I’ve got a 1997 Challenger 1800 and the gas gauge isn’t working. The low oil light does work. There is 12v coming into the gauge thru the purple wire as there should be. I’ve done all the diagnosis around the sending unit and the F1 fuse and all at the tank end are working as supposed to.

When power is applied to gauge the needle doesn’t move at all. Should ‘jump’ up a little to E once powered. With 12v on purple and ground to black - shorting across the pink and pink with black strip should show full. It doesn’t.

Everything I try and no motion on needle at all.
Anyone find a way to open these up and repair the gauge itself?

check ohms on fuel baffle it should have red wires coming pit if il not mistaken

 

[Doug Overkill]

Everything at the sending unit checked out. My issue was just a dead gauge. I buddy had one on his parts boat and now it works.

I was hoping someone would of had a fix for the gauge. This site is so good at a lot of things. Awesome SOP’s for the sending unit made that diagnosis a breeze. Well other than the upside down agony of getting it out of the boat.

 

[DesignAlot]

Everything at the sending unit checked out. My issue was just a dead gauge. I buddy had one on his parts boat and now it works.

I was hoping someone would of had a fix for the gauge. This site is so good at a lot of things. Awesome SOP’s for the sending unit made that diagnosis a breeze. Well other than the upside down agony of getting it out of the boat.

Hello, Doug. I have a 1999 speedster sk. I ordered a new fuel gauge aftermarket from Amazon. It is a 0-90 ohm. 0 being full, 90 being empty. This should work with the boat, I have already went all aftermarket with tachs and speedo. I was looking in the shop manual wiring diagram, seems there are two wires that go to the gauge from the fuel level sensor? My new gauge has one wire for sensor. Do you know which color from the oem plug I should use? Below is what I have come up with so far...

Purple/Pink +
Black - Neg
Blue - Lighting
Pink/Black - Fuel Sensor Neg
Pink - Fuel Sensor +
Light Blue - Oil sensor +
Pink/White

 

[Doug Overkill]

I don't know how different our boats are in regards to the fuel gauge. Mine is a 97 Challenger 1800 and in the end I got a gauge from a buddies 98 1800 and it was a different. It looked identical on the front and had the same wires with a different wire setup. The 97 had the wires integral with the gauge and came out about 20" of wire to a connector that plugged into the harness. The 98 gauge had a connector integrated into the back of the gauge housing and the harness came right up to it.

My 97 manual has this info of 6 wires at guage:
Purple - supply 12v +
Black - Neg
Blue - Lighting
Pink/Black - Fuel Sensor Neg
Pink - Fuel Sensor +
Light Blue - Oil sensor +

The fuel sensor has 3 wires
Pink & Pink/Black to/from gauge
and Pink/purple back to MPEM as low fuel sensor.

On my boat there (was) a momentary switch on the dash board that would silence the low fuel alarm when it sounded. The wire that fed this was Pink/White. I wonder if this is the extra wire in your setup.

Good luck.
Doug

 

[Doug Overkill]

Here is relevant area of my wiring diagram

 

[DesignAlot]

Thanks, Doug. Seems like the exact same setup in my boat. I have tried attaching the fuel sensor wire from the new gauge to the pink, and then I tried to the pink/black. I get full or empty. It is not showing 1/2 full like the factory gauge. I am going to do an ohm test at the tank where the sensor is, I will see if I get somewhere between 0-95 ohm. Then I am not sure how to connect the gauge properly. The pos, neg, lighting wires are simple enough. Just not getting the sensor wire to work. Someone else suggested that the black negative wire from the oem harness may go through the OEM gauge to the pink/black sensor wire that goes back out to the sensor. So wondering if I should jump the black to the pink/black and then try the pink sensor wire to the new gauge. Do you see anything dangerous about trying that?

 

[DesignAlot]

 

[Doug Overkill]

assumption. Your aftermarket gauge has 3 wires.
Black to ground
Red is 12v to sensor & light
Other is sensor

I would wire that with
Purple/Pink n/a
Black - Neg to light ground
Blue - Lighting to gauge light
Pink/Black - to gauge ground
Pink - Fuel Sensor + to other on gauge

This uses the pink/black & pink to ‘read’ sending unit.

Only other question I have, Is pink at gauge 12v or 5v?