Tips on how to fix a gas gauge doesn't work

Our cars are often molested fairly effectively by the point we get them.  Make sure that your wiring underneath the dash is in good shape.  If it’s not, I might counsel you start there.  Having seen some of these chimpanzees at work, you’re liable to seek out something beneath there.  Perhaps the problem.

 Most people are apprehensive with auto wiring.  It is really fairly simple and you may’t get hurt with it.  Just bear in mind your physique is the ground, and the wires carry the voltage.  BUT!  There are a couple of floor wires under the dash too.  So be careful whenever you splice something.

Here are the components
Gauge assembly
Sending Unit
Wiring from gas tank to dashboard.
Dash wiring.
Voltage Limiter (Regulator)

 There are FOUR of the commonest problems.

1.    Faulty Sprint Voltage regulator (Voltage limiter) or gauge

2.    Lost of a ground on the sending unit

3.    Break within the wire going to the sprint

4.    On some Chryslers, the Bulkhead connector on the firewall or connector behind kick panel.

Less Widespread

1.       Actual dangerous Sending Unit

2.       Fuel Gauge defective

 Tools needed for the basics:

Alligator Clip jumper (Make sure that it works)
Take a look at gentle probe
Radio Shack or equal Multi-meter

If removing the gauge cluster, you'll need a socket set, a couple of 2  Phillips screw drives and a pair of needle nose.

 Gas Gauge and Temp gauge doesn’t work. (Cause 1)

Let’s ask a easy question here.  Does the temp gauge work too?  Each the Temp gauge and the fuel gauge use a voltage limiter.  Given the best way these cares had been constructed, it is exhausting to get too get to that.  But before we dig into this, test the fuse for the instruments.  That fuse feeds the voltage limiter.  In time, voltage limiters tend to go bad.  If one burned out, it could have blown the fuse.  Which in a way is a good thing.  If the fuse is nice and the temp and Gas don’t work, then chances are high it’s considered one of two things.  Lost the bottom or the limiter is bad.

 After you are sure the fuse is sweet, (Test it with the Key ON), we are able to go for the checking for a ground to the cluster.  In case your cluster is back lit, and the dash lights work, chances are you have got a good ground to the dash.  If it’s front lit just like the Mopars of the early 70’s, then we have to examine the ground.  In case you have any lights on the dash, oil gentle (Fool Light) turn sign indicator they usually work, then a floor is established.

 If all these items are good, then you need to go for the voltage limiter.  This is the place the enjoyable starts.  Relying in your brail expertise, it is best to be able to a minimum of discover it on the back of the cluster.  If you happen to can’t, you then’ll need to take away the cluster.  A superb suggestion here is to be sure to have some other below Dash tasks on an inventory able to be done.  I strongly advise you disconnect the battery whereas removing the cluster.  Once out, you may reconnect to complete your test.

Since you're going this far, it’s a good idea to just substitute the regulator anyway.  They are available from NAPA or any respectable auto elements store.  Most of those chains don’t know something about it except it’s within the computer.  Keep in mind, you're dealing with people who only need a license to breath within the big chains, Brains weren’t utilized for.

 Just the gas gauge is out Supplement

IF the dash cluster has a printed circuit board, double examine to be sure it’s in tact and there are no burned traces.

Take your take a look at light and connect the one end to ground.  Activate the ignition key and check the back of the gasoline gauge.  On the crimson wire, (I feel it’s red. . they vary) it's best to get a dim pulsing light.  If that is present, then you might want to remove the gauge and examine it.  Look at the back of the gauge when it’s removed.  Ensure that the wires are related to the posts.  Be sure that the coil isn’t charred black or cooked.  If it’s charred, the gauge is completed and your cause it doesn’t work.  Start trying round for a cluster.  I found it cheaper to buy a whole cluster than just the gauge.

 If it gauge does work: (Reason 2)

 The quickest technique to determine if it’s the wiring, bulk head connector, or the voltage to the gauge is to floor the wire at the sending unit.

 Use an alligator clip jumper and ground the wire to the sending unit to a chassis ground.  Activate the important thing and see if the gauge goes to full.

 Reconnect the wire to the sending unit.  Using the same alligator clip jumper. Floor the sending unit to the body.  If the gauge works, you understand what it's a must to do.  On non-molested vehicles, there's normally a clip that jumps across the rubber hose from the sending unit nipple to the gas line.    This clip establishes a floor between the sending unit and the body.

 If it is current, merely twist it round to re-establish a ground.  Over time, corrosion develops, loosing the ground.  A generous software of simple Vasoline around the ends of the taps will stop it from occurring again.

 Before you go any additional, let’s ensure that the sending unit is working.  You can get a normal thought if the sending unit is working by checking it for resistance through the use of a simple multi-meter.  Set your Multi-meter to zero-a hundred Ohms.  By now you understand how your car, so guess at how much fuel is in there and take a reading accordingly.  A full tank will learn 9 to 10 ohms.  An empty tank will read 96 to ninety eight ohms.  Put the red probe from the meter to the center publish in your sending unit, and the black to the body.  Try using it to the fuel line too.  If you happen to get something in between those two parameters, we will at the very least determine it’s putting out something.  If the multi-meter is studying 50 ohms, for instance, then you've roughly half a tank.  If there isn't any reading in any respect, then guess what?  Run the tank down and take away the unit.  Nonetheless, in case you are getting a reading, then it’s sufficient to activate the gauge.

 The gauge doesn't work: (Cause three and four)

 This is a little tougher as a result of some vehicles are available by means of the bulkhead connector or run via the body.  You have to have a look at the tank wire and see if it enters the physique on the trunk or under the rear seat.  Normally it could head towards the drivers side.  Most circumstances, the wire goes into the cabin and joins the tail gentle wiring.  Be aware the color of the wire on the tank.  Almost definitely it will be the same shade to the subsequent connector.  From there it might change.  Often a blue or black wire.

 Let’s use a 71 Fury for example

If the gauge doesn't work, we have to work our means forward.  Reground the wire to the sending unit with the alligator jumper.  Take away the driving force sidekick panel and find the multi-connector going to the rear of the car.  Examine for corrosion and broken wires.   Decide which wire is the sending unit wire.  Within the seventy one Fury it’s a shiny blue wire.  Join your test light to a hot place on the fuse block and take a look at it to ground to ensure it lights up.  Disconnect your connector and verify to see if the sunshine goes on by probing the plug that goes back.  If it lights up, the wire is nice to that point.

 OK Put the tank again together and ensure you’ve maintained a good ground.  Put the automotive down, we’re finished back there.

 Only for the heck of it, poke a ground wire into the connector that goes up into the dash and see what happens.  Turn on the important thing and see if the fuel gauge comes up.  If it does, go back and verify you wiring to the back again.  Smear some Vasoline on the connections and reconnect the plug.

 Still not working?  I assume you haven’t put the cluster again in by now.  My suggestion can be to double-test your ground to the cluster once more at this point.  In case you changed the voltage limiter as talked about in part one, all the things needs to be in order.  You’ll should repeat the first step over again.  If the gauge is in good situation, and the dash cluster is so as, it's worthwhile to repeat all these steps.


Right here is an concept on tips on how to floor the sending unit to the body.
Strip a chunk of wire, calmly sand a small spot on the sending unit gasoline nipple.  Utilizing a small hose clamp, clamp the wire to the nipple.  Smear some Vasoline or a dot of grease on the connection to stop corrosion.  Connect the opposite end to the physique with a screw, or slip it underneath a bolt someplace nearby.  Be certain that the physique connection is clean.  You possibly can grease that too when you want.

 This is not as difficult as it sounds.  In case you are fairly good with tools, you should be able to diagnose and possibly repair the gauge or gauges in half a day, and that’s permitting for time to run to the elements store.

 Attempting to tell you how to do this is tough with so many different engineering schemes out there.