Author Topic: Fuel gauge not working  (Read 1388 times)

0 Members and 1 Guest are viewing this topic.

Offline FNQ TRX

  • antrx.com full member
  • ***
  • Posts: 135
  • Karma: +0/-1
  • Gender: Male
  • Bread, butter and bacon is how I roll.
Fuel gauge not working
« on: Aug 17, 2015, 02:33PM »
hello all.  I searched through the threads, but couldn't find any definitive answers...

The fuel gauge in the pinny (U12 TRX) works sometimes, but not others.  The 'tap on the dash' trick sometimes gets it going - but not always.

Is this a fault in the sender unit or (as I suspect) a connection in the dash?  Is there a known fix or suggested repair? ???
Old guy who should know better than to mess around with old cars.

Offline noss

  • Administrator
  • post whore
  • *****
  • Posts: 13880
  • Karma: +275/-50
  • Gender: Male
  • great scott!
    • antrx
Re: Fuel gauge not working
« Reply #1 on: Sep 1, 2015, 10:44AM »
if the fault is with the sender, check that the arm on the float hasn't seized, it can happen if the car has sat for a while.

to check the sender, get a multi meter onto the wiring and check if the voltage changes when you move the float arm up and down.

you can go through the FSM (http://www.antrx.com/smf/index.php/topic,7177.0.html) and have a look at the voltage ranges you should be expecting.

http://polyfedelicio.us/imgs/ - free image hosting for whatever you like

Offline pedro666

  • post whore
  • *****
  • Posts: 2326
  • Karma: +26/-8
  • Gender: Male
  • VET NEO VVL is how I roll...
Re: Fuel gauge not working
« Reply #2 on: Sep 2, 2015, 06:27PM »
if the fault is with the sender, check that the arm on the float hasn't seized, it can happen if the car has sat for a while.

to check the sender, get a multi meter onto the wiring and check if the voltage changes when you move the float arm up and down.

you can go through the FSM (http://www.antrx.com/smf/index.php/topic,7177.0.html) and have a look at the voltage ranges you should be expecting.
Ya , I had this problem before when I put the new fuel pump in. The cradle arm was sitting funny, like noss said. Maybe sticking

Sent from my HTC_E9pw using Tapatalk

the words "race car" spelled backward still spell "race car"? 




skype_shannan801

Offline FNQ TRX

  • antrx.com full member
  • ***
  • Posts: 135
  • Karma: +0/-1
  • Gender: Male
  • Bread, butter and bacon is how I roll.
Re: Fuel gauge not working
« Reply #3 on: Sep 4, 2015, 11:54AM »
Cool.  I will have a look.

It's just that sometimes when I tap the dashboard the fuel gauge springs to life - a bit like the temp gauge.  I was thinking that it might have been a loose connection of some description in the dash?
Old guy who should know better than to mess around with old cars.

Offline FNQ TRX

  • antrx.com full member
  • ***
  • Posts: 135
  • Karma: +0/-1
  • Gender: Male
  • Bread, butter and bacon is how I roll.
Re: Fuel gauge not working
« Reply #4 on: Oct 24, 2015, 01:43PM »
Finally got around to pulling out the fuel pump and gauge sender unit.  it was not as a big a job as I imagined.

The float is freely moving and everything looks fine.  Cleaned and lubed all moving parts and re-installed. 

The gauge is still not working so expect that one of the electrical components may be stuffed.  I did put a multimeter over the sender unit and moved the float up and down.  I did see a change in resistance, but I don't know what it should actually be reading.  There is a capacitor (or something) on the side of the sender unit, so I wonder if that could be stuffed?

Anyway, I will drag the car's sorry backside into an auto electricians this week for a closer look.

Meanwhile, the trip meter is a good indication of how much is remaining...

It seems to be averaging around 14litres per 100 km around town (aircon always on and in the tropics) - and yes it has been tuned and checked over!! - so when the car gets to around 400kms on a tank it is time to fill up.

Loving the old car experience!  Have a good weekend all.
Old guy who should know better than to mess around with old cars.

Offline FNQ TRX

  • antrx.com full member
  • ***
  • Posts: 135
  • Karma: +0/-1
  • Gender: Male
  • Bread, butter and bacon is how I roll.
Re: Fuel gauge not working
« Reply #5 on: Oct 25, 2015, 08:14PM »
And wouldn't you know it...

The gauge started working again today.  What is with that? :o

I am inclined to think it could be something at the dash end, so my auto-electrical mate can diagnose what's going on.  Stuffed if I know.
Old guy who should know better than to mess around with old cars.

Offline pedro666

  • post whore
  • *****
  • Posts: 2326
  • Karma: +26/-8
  • Gender: Male
  • VET NEO VVL is how I roll...
Re: Fuel gauge not working
« Reply #6 on: Oct 26, 2015, 11:23PM »
you must have abused it and threatened to replace it...usually how it goes
the words "race car" spelled backward still spell "race car"? 




skype_shannan801

Offline FNQ TRX

  • antrx.com full member
  • ***
  • Posts: 135
  • Karma: +0/-1
  • Gender: Male
  • Bread, butter and bacon is how I roll.
Re: Fuel gauge not working
« Reply #7 on: Oct 26, 2015, 11:33PM »
hahahahaha! :D

Spoke much abusive language toward the busted handbrake cable as well.... unfortunately it hasn't fixed itself.

Old guy who should know better than to mess around with old cars.

Offline FNQ TRX

  • antrx.com full member
  • ***
  • Posts: 135
  • Karma: +0/-1
  • Gender: Male
  • Bread, butter and bacon is how I roll.
Re: Fuel gauge not working
« Reply #8 on: Nov 28, 2015, 08:32PM »
Pulled out the sender unit a couple of weeks ago.  Works well and has resistance drop etc. with movement.  The arm moves freely and there appeared to be no problems at the fuel tank end.

The fuel gauge still had the same issue of only working intermittently so out came the dash and instrument cluster.  Hit all the connecters and plugs with contact cleaner and gave the gauges a bit of a spray as well.

Put it all back together and the gauge works nearly every time the car starts though occasionally requires a tap on the dash - which also helps to get the temp gauge working!  Old cars......
Old guy who should know better than to mess around with old cars.