Fuel Level Connector
Fuel Level Connector
As you can see the connector has corrosion and this is before I cleaned it up pretty good. The corrosion changes the resistance going to the fuel gauge giving me different responses of the fuel level. After I cleaned it up it went back to what it use to be for a while but after I washed my car last night and spraying that area it went back to changing levels and dropping below empty in a matter of minutes.
Joined: Jun 2008
Posts: 8,376
Likes: 28
From: Chino Hills, CA
There's supposed to be a plastic inner fender piece between the wheel well and the tank/sensor. Likely you'd have less trouble with this if that piece was where it's supposed to be.
Also, the sensor gets its reference for ground through the round base that it mounts to. Over
time the contact between the base and outside part of the sensor that connects to the base for
that ground gets weak, so the resistance goes up. The way the gauge works is the higher the
resistance value, the more towards empty the needle points.
You can fix this without remove the sensor from the tank. You need to ground the base of the
sensor to the round base that bolts the sensor assembly into the tank. I did this by running a
wire from the sensor base and putting it under one of the mounting screws.
time the contact between the base and outside part of the sensor that connects to the base for
that ground gets weak, so the resistance goes up. The way the gauge works is the higher the
resistance value, the more towards empty the needle points.
You can fix this without remove the sensor from the tank. You need to ground the base of the
sensor to the round base that bolts the sensor assembly into the tank. I did this by running a
wire from the sensor base and putting it under one of the mounting screws.
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Also, the sensor gets its reference for ground through the round base that it mounts to. Over time the contact between the base and outside part of the sensor that connects to the base for that ground gets weak, so the resistance goes up. The way the gauge works is the higher the resistance value, the more towards empty the needle points. You can fix this without remove the sensor from the tank. You need to ground the base of the sensor to the round base that bolts the sensor assembly into the tank. I did this by running a wire from the sensor base and putting it under one of the mounting screws.
Well got it all working, but two things, it tells my my real fuel amount when the key is turned with the dash lights on but when I start the car the gauge drops down about 1/4 tank of what the real fuel amount is and the fuel light stay on and blinks (from fuel moving around?) Maybe it'll fix itself or something lol but I got it all working just there is a bug to it. Anybody have ideas of what this little bug could be?
Last edited by Jere Urso; Mar 26, 2015 at 08:30 PM.
Joined: Mar 2001
Posts: 31,833
Likes: 3,232
From: https://www2.mazda.com/en/100th/
Well, found out that my ground caused parasitic load and my battery is now low and won't start my car so I threw it on the charger. Disconnected my ground until I figure out what's going on. Does anybody know how this fuel sending unit is wired or ever looked at the inside of it to help me out because I need it.
So while reading that, my ground wire has to be ground to the rivet in the middle of the baseplate and its not. That must be the reason it's all screwy, now I gotta figure how to get a good attachment of my ground on that corroded rivet.
Joined: Jun 2008
Posts: 8,376
Likes: 28
From: Chino Hills, CA
remember now and then tucked the other end under one of the screws holding
the assembly to the tank.
Well, now its actually all working, after cleaning the copper contact where the old ground broke off I basically just dumped solder between the two connections to make sure it wouldn't break free. After I took this picture I heat shrunk electrical tape over the connection. If corrosion ever eats your ground for your fuel level sender, this is something you could do.
Last edited by Jere Urso; Apr 8, 2015 at 09:31 AM.
Would the low fuel light come up if the gauge doesn't work? If the light illuminates with the others before starting means the connection is good? The ground must not be good enough because the gauge on the dash just quit working after a week of working lol Such a pain.
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