Temperature Gauge Sender Fault

[ipaulog]

For some time I've had a fault on my temp. gauge - it doesn't make it anywhere the normal running temp. mark of half way.

The wiring into the sender has been bodged by someone in the past so this may be the cause. It is an early type ('83).

There is just a single wire into the unit so I presume the part is the first one of four on the list from Euro Car Parts which is described as single pin (Dansk), the other three being 2 pin. Does the sender come with the wire as part of it or a particular type of connector - it's hard to work out due to the bodge.

Also can anyone enlighten me as to the purpose of the switch in the end of the unobtainable metal water pipe above the thermostat housing?

I have found my Haynes less than useful.

Thanks for any help in advance,

Paul.

[Aidan]

The switch is a temp switch that switches on the carb heater and choke feedback circuits, and switches them off when coolant reaches correct temp.
Before worrying about the guage check that the engine is actually upto temperature properly, ie if you leave it standing for ten mins or so when warm the fan will cut in because the temp is just high and the guage is showing just high. It's possible that your thermostat has failed open in which case the engine will never reach the correct temp and will run at about half of what it should be.
Single connector is a round brass bush which takes a 6.3mm female spade