Temp gauge problem

Hi my temperature gauge on my 300tdi auto never reads above 'C' even when the engine is hot and the rad is hot all over?

I changed the temp sender in the head and it hasn't changed the reading?

Any ideas guys???

Cheers
Daz

I have just bridged the wire from the sender end to the engine and the temp gauge goes to the top - i'm still stumped!

Daz

Wrong sender. Or no thermostat.

Thermostat is working correctly as i changed it for a new 1 and checked it opens when the engine is hot. The 300tdi sender i got from ebay with the green insert - just wondering if its the connector on the wire to the sender?

Daz

Is it easy to test the sender? Have got a multimeter with the ohms scale as the sender probably works through resistance. Any ideas what the ohms readings should be for cold & hot?
Daz

Do yo other gauges work ok?

Yep rev counter works and everything else works ok.
I'll buy a new sender and change it see if that sorts it out.
Might buy a new sender plug connector too.
Daz

UPDATE: the sender body is still in the thermostat housing but the head/connection and the internal spring are out!
Looks like the head has broken off the body !
Its not leaking as the body of the sender and 99% of the thread is still in!
BUGGER!

Anyone know if its a simple job to take off the thermostat housing without removing the head etc...........

Cheers
Daz

Yes, you can remove housing, and you have a "green" disco sender. You need a "black" defender sender.