Temperature gauge keeps fluctuating whats the cause
Fiats have a reputation for electrical/electronic problems as they age and even when they are not very old they can manage strange things that even sometimes defeat the dealers, though the same can be said of many modern vehicles. I used to look after a Ducato motorhome and fortunately didn't need to get involved with much electrical work - the only faults were caused by the coachbuilders rushing around and being careless and not by Fiat.
I am not sure if the temp gauge is driven by the engine management or is a traditional circuit but either way the temperature gauge is in effect a voltmeter of sorts. Assuming the gauge is ok, the reading will only fluctuate if the voltage in the circuit fluctuates and that could mean the supply voltage is fluctuating or the resistance of the ground path is fluctuating.
With the traditional circuit the gauge is supplied by an electronically stabilised voltage and the ground path resistance is varied by the engine coolant temperature sensor and fluctuations could be anything from a faulty instrument voltage regulator, through faulty wiring or connections to the temperature actually fluctuating.
If the gauge is driven by the engine management the same approximately applies but checking the circuit becomes much more complex due to the need for circuit diagrams and specialised test equipment, though these would not be needed just to check the security of the gauge in the printed circuit of the instrument panel.
Mar 18, 2017 |
Fiat Cars & Trucks