fuel and temp gauge

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Ads
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fuel and temp gauge

Post by Ads »

the fuel and temp gauge on my cav turbo has been acting up, the fuel gauge never goes above half even when the tank is full, and it dosnt drop below a 1/4 when empty, and the temp gauges goes up to the red slowly at first then a bit quicker, and stays on the red, my aftermarket temp gauge I have fitted shows the correct temp, and rarely goes over 90 degrees, anyone any ideas what wrong with the oe gauges. Ads
iangsi
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Re: fuel and temp gauge

Post by iangsi »

Fuel gauge will be the sender in the tank had the same problem on my GSI . Temp again the single wire temp sender.
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Robsey
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Re: fuel and temp gauge

Post by Robsey »

Hmm - not so sure.

The temperature gauge scenario does not add up.

If the sender was faulty, why should the aftermarket gauge work?

Hmm - I would question the circuit board foil on the back of the instrument cluster.

Both require a good 12 volt feed, and are grounded via the relevant sender.

To test the tank sender, short the sender connector pins with a decent wattage 120 ohm resistor.
The fuel gauge should read just above the red area.
Any variation on this suggests a faulty gauge or it's wiring.

The temperature sensor on the thermostat housing is quite cheap and easy to replace, so not too expensive to test by substitution.
Ads
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Location: Sunderland

Re: fuel and temp gauge

Post by Ads »

Robsey wrote:Hmm - not so sure.

The temperature gauge scenario does not add up.

If the sender was faulty, why should the aftermarket gauge work?

Hmm - I would question the circuit board foil on the back of the instrument cluster.

Both require a good 12 volt feed, and are grounded via the relevant sender.

To test the tank sender, short the sender connector pins with a decent wattage 120 ohm resistor.
The fuel gauge should read just above the red area.
Any variation on this suggests a faulty gauge or it's wiring.

The temperature sensor on the thermostat housing is quite cheap and easy to replace, so not too expensive to test by substitution.
Robsey - the after market gauge has its own sensor, plumbed into the pipework, and the original gauge is still on original sender in the thermo housing, sorry for any confusion. Ads
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Robsey
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Re: fuel and temp gauge

Post by Robsey »

Ah okay -
In that case, it would be daft not to replace the sender with a new one, as the price is quite cheap for one andit is a very quick and easy fix to do..

The fuel tank sender is a different story.
A bit of a faff to get out, and not particularly cheap.
In that case it is definitely worth testing the fuel gauge first using the 120 ohm resister.
(Don't use a skinny piddly resister as it will get quite hot quickly).
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