Temperture meter problems

[killick]

Following the advice received on my previous enquirery I have checked my boats temperture meter by turning on the ignition,removing the wire from the sender, and earthing it. Results: On engine block next to sender meter reads 25% .On impeller pump housing 50%. On copper fuel line 100%. Directly to battery negative terminal 100%. Any advice will be greatly appreciated

 

[seadog30]

Temp Instrument Misreading

Hi

Had the same problem myself, its a poor connection on the earthing / neg circuit. Make sure that the connection (normally thick black wire) is has got a clean connection between the terminals on both ends between the 12V neg and the engine block. Also make sure that the wires to and from the Temperature instrument are all well connected on bare metal connections.

Once its fixed go round all of the cable connections and clean and grease them with a smear of vasaline.

Good luck

 

[lenseman]

Following the advice received on my previous enquirery I have checked my boats temperture meter by turning on the ignition,removing the wire from the sender, and earthing it. Results: On engine block next to sender meter reads 25% .On impeller pump housing 50%. On copper fuel line 100%. Directly to battery negative terminal 100%. Any advice will be greatly appreciated

OK, get a spare car jumper lead which most people have somewhere and using only one of the car jumper leads, either the black or the red one, connect one end of it to the battery negative and the other to something earthy and substantial on the engine. Then again try shorting out the temperature sender lead down onto the engine block.

It should read 100% Full Scale Deflection (FSD). If it does then your engine earth lead to battery negative needs cleaning/replacing/tightening up?


.

 

[VicS]

Results: On engine block next to sender meter reads 25% ......Directly to battery negative terminal 100%

This implies, as others have said, a very bad connection between battery negative and the engine block.

So bad that other instruments and warning lights probably wont work properly either. The glowplugs, if you have them wont work. Starting the engine is likely to be difficult/ impossible and even if it runs the charging is likely to be next to nothing.

However maybe your battery neg connection goes to the starter motor, thereby ensuring good starting . If so then you will be looking for a poor connection between there and the block.

What engine ??

 

[pampas]

run a tap of the correct tpi and clean out the old thread, have come across this solution in 40 years.

 

[killick]

Thank you all for the advice. I now have a much better understanding of the problem