Open up gas tank?

[Dylanb23]

So my gas gauge doesnt work on my 521... Im wondering if the Floater is out of wack....

 

 

 

I can access it from in my bed...

And how hard is it to open that thing up?

 

It seems to be a little rusted

 

Will i blow up?

Combust into flame?

 

What should i do?

[datzenmike]

Before you blow up....

 

Check that the tank is well grounded. Has to be grounded for the gauge to work.

Next, ground the Yellow sender wire to test that it's working.... gauge should read FULL with key on.

[Dylanb23]

Where is the ground at?

 

If its the back wire on top next to the yellow then im solid...

 

if theres another i dont know about...

but I roughed up the connections to the tank with some steel wool so those are nice and tight.

[Cahoon520]

Does your temperature gauge work? If not its most like your voltage regulator for the gauges.

[datzenmike]

Next, ground the Yellow sender wire to test that it's working.... gauge should read FULL with key on.

 

This will tell you a few things. If the gauge does not move then the problem is likely the gauge or the wiring back towards the gauge and not the sender. If the gauge reads full then it's the sender unit.

[Dylanb23]

Temp gauge works fine.

 

Gauge doesnt work at all.

 

I move the wires around and theres absolutely no movement.

[521rat]

nice, i needed info on this too. ill have to check mine out tomorrow. hope i can get it working. hate having to randomly put gas in...

[Dylanb23]

yea i kind of just drive for a while... fill up.. drive... cross fingers... drive... fill up....

 

I have a extra 2 gallon just in case

[datzenmike]

Next, ground the Yellow sender wire to test that it's working.... gauge should read FULL with key on.

 

 

This will tell you a few things. If the gauge does not move then the problem is likely the gauge or the wiring back towards the gauge and not the sender. If the gauge reads full then it's the sender unit.

 

So you grounded the yellow wire with the key on and the gauge does not move????

[Dylanb23]

No movement...

[datzenmike]

OK. Normally power flows through the gauge to the tank and through the tank sender to ground to make the gauge work. The tank sender has a variable resistance that is high when empty and low resistance when full. Grounding the yellow wire simulates a full tank.

 

Your results would indicate that there is no power coming from the gauge to the sender in the tank. Now, this could be a gauge that is bad, or simply a loose connection or broken wire between gauge and tank.

 

I had a 521 and seem to remember there is a harness plug under the passenger seat. This plug connects the interior harness to the exterior harness that goes back along the right side of the frame. It contains the rear marker, license light brake lights... and the fuel gauge wire. Un plug and ground the Yellow wire going back towards the dash gauge.

 

Again, if the gauge starts working then the Yellow wire in the harness under the truck is broken.

If the gauge does not work, well it's starting to look like a bad gauge.

 

The harness under the truck is exposed to water and dirt and the occasional flying rock damage.

[metalmonkey47]

Good info mike

 

I needed some info on this. LOVE how Ratsun teaches you shit un-expectedly.

[datzenmike]

Good info mike

 

I needed some info on this. LOVE how Ratsun teaches you shit un-expectedly.

 

:lol:

 

I had forgotten but I think my gas gauge quit on my 521 once. The rear tail lights were also a problem at times. I unwrapped the rear harness and found a PO had wired in a trailer plug and then cut the plug off and tapped it up. Salt water got in and rotted the bare copper wires where they were twisted together... no solder just twisted together!!!!!! 'kin previous owners! I replaced the harness and it was good.

[skunk]

the gas tank needs a ground.... i dont think mine has one :unsure: theres a yellow wire but i dont see any other wires. Im glad i read this thread.