Bongo Fury

I've just carried out the modification to our V6 temp. gauge per the fact sheet. The Zener diode has been shorted out and a 100 ohm resistor fitted across the terminals. The modification has made no difference to the gauge operation. It still goes to 40% then stops. Has anyone modified their gauge and had the same problem?

How did you short out the Zener ?

Can you move the needle by hand? There was a comment on here not that long ago about a fuel gauge (I think) which was not moving as expected & it was traced to a problem with the needle getting stuck on the plastic dial at particular point in its travel.

Have you done the earthing mod to the fuel tank itself? Listed in the Fact Sheets.

The Zener was shorted out with a short length of tinned copper wire soldered across the terminal wires exactly as per the photo in the fact sheet. I was unaware of the fuel tank earth as it is not mentioned in the fact sheet. How does the fuel tank earth affect the temperature system?

Fuel tank earthing issue is nothing to do with temperature gauge. It's only relevant to diesel Bongos where the fuel gauge sometimes stops working.

The symptoms sound just as if the Zener has not been shorted, might be worth checking with a meter that it is indeed shorted.

JoeC wrote:Have you done the earthing mod to the fuel tank itself? Listed in the Fact Sheets.

Sorry, ignore me. I must have been day dreaming at work

Thanks Geoff, I'll check the Zener shorting tomorrow.

I read (some where) that just using a resister and not linking the gauge wires together would work, so I just fitted a resister ..



I find when I turn on the ignition the Temp. gauge goes up about a third and basically stays there with no obvious fluctuations .. up or down ..

Its the Zener that causes the meter to "pause" in its range, so whilst the resistor will change the scale position,leaving the Zener in circuit means it will just pause at a different setting.

Checked this morning, shorting link OK but replaced it in case of a dry joint. Now works as advertised. A bit disconcerting seeing the needle go to about 65% of the range but I know the system is rock solid so no worries. Thanks for all the help!