# Hymer 544 temp gauge



## redjumpa (Sep 5, 2008)

Can anyone offer advice to a novice owner and a hopeless mechanic.

The temp gauge on my 1991 544 (2.5 Fiat Ducato) has stopped working, I don't think it is a fuse issue because (I think!!) it is a shared fuse with other items that are all working.

Any help would be appreciated as I don't relish driving around guessing how hot the engine is ruuning.


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## gaspode (May 9, 2005)

Hi redjumpa

Temperature guage faults depend on whether the guage is mechanical or electrical, yours is probably electrical and the fault will almost certainly be in order of likelyhood:
1) Wire to sender unit come adrift (sender unit located either on side of engine block or on the thermostat housing, it will have a single wire going to a terminal on top of it).
2) Break in said wire.
3) Sender unit faulty.

First you need to locate the sender unit, pull the wire off the terminal, turn on the ignition and short the wire to earth. The temperature guage should shoot to the top and back to zero when you remove the wire from earth. If this happens you have a duff sender unit, if nothing happens you have a wiring problem or a duff guage (unlikely).

New sender units are a comparatively cheap replacement but can be very difficult to remove (they screw in and the threads are usually affected by corrosion on older engines).


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## redjumpa (Sep 5, 2008)

Thanks Gaspode ....... even for me that sounds like something I can at least check before passing it to an expert if it is the sender and it is corroded in place.

Thanks again


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