Errotic thermostat


Have got an erratic thermostat reading in the SPORTRAK M reg. Looks like power surges to the needle, the heater is still working fine and the engine is not over heating.
Could some one inform me is this normal or is it faulty.
Any advice appreciated.
Regards Greengrass.


Dont quite understand your post!
Perhaps you could repost again and clarify your problem.
Erratic thermostat reading ??????
Power surge to needle ????????


Yes guys it is the thermostat I meant. It does not seem to stay in one place on the gauge just keeps flickering from side to side. But the Sportrak still runs well and is not over heating.I will have a look at Daz,s idea. Thanks for posting back to me its really appreciated.
Regards GG.

A thermostat is a device that

A thermostat is a device that allows/stops water flowing through the cooling system. Thermostats are set at a specific temperarture and will open up when this temperature is reached and allow the radiator fluid to flow into the engine.
This helps with quicker warming up of an engine (by keeping the same water in the engine) and then allows it to cool when up to operating temp (by letting the water pass into the radiator).

A temperature gauge is what it on the dash and is controlled by the sender unit that resides in the water passage in the engine block.

I would check the sender unit first, as these are known to malfunction quite often.


Hi Greengrass,

do you mean the temperature gauge? I must admit like Mace i did have some problems understanding your desription and had a laugh at your 'Errotic thermostat' in the topic headings.

The temp gauge and fuel gauge both run on a regulated voltage of about 5-7volts. The regulator is built in to the fuel gauge and the temp gauge feeds from there. If you can get to the back of the gauges and find the two terminals on the back of the temp gauge, one of them should have (i think) 5-7 volts, with the ignition turned on and the other should be a direct connection to the temperature sender unit (positioned somewhere near the back of the cylinder head).

Hope this gives you some pointers to help you locate the problem, Daz