# Fuel gauge



## moblee (Dec 31, 2006)

Hello 

I'm just back from France where I used Gas oil & Gazole depending on what pump I was at  

Now my gauge is going from Full tank to empty to half full, all over the place.

I think it's a sticking float....... could I add a Diesel cleaner additive to the tank to free up any sludge ?

P.s (I'm blaming myself & the Grade of Diesel I've used).


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## gjh613 (Aug 7, 2011)

I think that your fuel gauging problem is more likely to be an electrical fault than an issue with the French diesel - I use Total diesel, almost exclusively, without any problems!

It might be a good idea to check the electrical connections to the tank sender unit to ensure that they are in good condition with no corrosion of damage to the connectors and cables. Similarly, check the connections at the instrument panel. If the temperature gauge is also playing up, the problem may be associated with the instrument voltage regulator.

Hope you get the problem sorted soon!


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## BillCreer (Jan 23, 2010)

Hi,

You can shove any diesel in your tank and it will not make your float stick or have any noticeable effect on your engine.
Sounds like there might be a problem with the sender/ float or, as has been said previously, an electrical fault.


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## 747 (Oct 2, 2009)

There is a printed circuit board behind the speedo and they can fail. I hope it is not this because they are very expensive (for what they are).

I read recently that a much cheaper option is to remove the circuit board and re-solder it. It is usually a 'dry' joint that causes the problem and soldering cures it. Any decent auto electrician should be able to do this at a fraction of the cost.


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## salmonfisher (Jan 3, 2011)

*Fuel guage*

Hello. Its unlikely its the float. First check the earth on the guage unit, ie clean it up. Then check the wiring diagram for the fuel guage. There is usualy a balast resister unit behind the clocks on the dash. Hope this helps. John.


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## raynipper (Aug 4, 2008)

My fuel gauge variations changed with the hooter. It was an earth below the horn in the engine compartment left side.

Ray.


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## Geriatricbackpacker (Aug 21, 2012)

Hi, just upgraded (?) to a Hymer 584 and it had a dead fuel gauge (together with illuminated low fuel light) which hadn’t been mentioned by the vendor. It worked momentarily as we drove it back to Norfolk through the driving rain in the peak district but resorted back to zero as soon as the weather perked up. I have followed the advice from many forums and have had the tank cover up, dismantled the horn, taken the dashboard apart, cleaned all the earthing terminals and thumped the vehicle in numerous places (some as a result of what I had read and some from pure frustration!) 
Today whilst checking the VIN number in order to transfer a cherish number plate I saw that affixed to the bulkhead in the engine bay were a couple of relays I hadn’t noticed before. I jiggled the relays and twiddled the wires in the vain hope that this would solve the problem. I was pleasantly surprised to find that the gauge has started to work again and seemingly giving an accurate account of what fuel I suspected the tank held. The low fuel warning light is still on which is probable due to a sticking float which will be tackled at a later occasion or just tape over it!
The relays are slap bang in the middle of the bulkhead when you open the bonnet (or letterbox as I like to refer to it). Mine are both black and have a mess of wires leading into them. As I said a gentle jiggle and twiddle was all it took. If the problem persists at least I will have a point of reference to start from. I have taken some photos of the position relays if they would be of any help to other members.


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## CurlyBoy (Jan 13, 2008)

Had a similar problem, RAC friend suggested the following procedure. Disconnect BOTH battery leads, connect a 12v bulb between them to completely drain the wiring system of all residue electricity, then reconnect the battery. This in effect resets the ECU. It worked for me.
curlyboy


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