fuel guage repair

skater_kat

i have a 10 year old diahatsu hijet van.

the fuel guage has been broken since i bought it over a year ago.

it is getting to be a proper pain as depsite my pre-emptive petrol purchasing strategy, i have had to be towed off the road about 4 times in the year.

people have told me that getting it fixed is "really expensive" and i shouldnt bother.

can anyone tell me how much this kind of job would cost, and is there any possibilty of getting some kind of external guage fitted if this would be cheaper.

thanks

TonyMMM

Depends why it's not working - most likely to be a faulty sender unit which is usually a quick and easy fix....but you will need to carry out a few tests. It could be the sender unit, the wiring, a faulty connection or the gauge itself (probably the least likely).

Technical_Dave

Fuel gauges aren't particularly complicated, especially on a 10 year old van. There's 2 parts to the system, a sender and the gauge. The sender fits into the fuel tank and is essentially a float on an arm, which is connected to a variable resistor. There will be a 12v feed into the sender, and depending on how high the float is in the tank, a voltage between 0 to 12 out. This is then fed directly into the gauge, and the higher the voltage the further up the gauge the needle will go.

Do you have a multimeter and the ability to operate a screwdriver? If so, get in behind the dash the ckeck the feed in to the gauge (with the ignition on). If you have volts there (and the earth to the gauge is good) then the gauge is dead. If no volts, then check the feeds in and out of the sender to see if that is working properly. Depending on the design, you may be able to remove the sender fairly easily and test it on the bench to see if you get a nice smooth voltage increase as you move the float up.

marlot

TonyMMM wrote: »

Depends why it's not working - most likely to be a faulty sender unit which is usually a quick and easy fix....but you will need to carry out a few tests. It could be the sender unit, the wiring, a faulty connection or the guage itself (probably the least likely).

I agree.

Fairly easy to test if you (or a mate) are handy with a multimeter

skater_kat

thank you. i will see if i can borrow a multimeter and give it a go!!

RichGold

A cheaper alternative would be to carry a 5 litre jerrycan with petrol in it.

vaio

Pull the wire off the sender, gauge should move to an extreme end (might be full or empty)
Short the wire to the tank or other bare metal earth, the gauge should move to the other extreme

If both the above happen then the fault is in the sender, if they don’t then the fault is in the gauge and/or wiring.

On a “high quality” vehicle like this it’s entirely possible the connect to the sender is exposed to the weather/road salt etc in which case (if you are lucky) you might find the connection has become detached/corroded and just needs reattaching or remaking so an easy & cheap fix

vaio

RichGold wrote: »

A cheaper alternative would be to carry a 5 litre jerrycan with petrol in it.

nice thought but a full jerry can would take up most of the carrying capacity of those little vans

gardner1

How hard is it to fill tank up with say 10 gal at 40 mpg=400 miles and reset the trip everytime

vaio

gardner1 wrote: »

How hard is it to fill tank up with say 10 gal at 40 mpg=400 miles and reset the trip everytime

very hard on one of those, the tank doesn't hold anywhere near 10 gals

Lum

RichGold wrote: »

A cheaper alternative would be to carry a 5 litregallon jerrycan with petrol in it.

Fixed that, but yes I agree with your point.