Senders, gauges and fluids.

Almost finished rewiring my 300tdi. Just the gauges to go but so far its not gone well.

I'll start with the coolant. I connected it up 12v>guage>sender. Now looking at the back of the gauge there is a female and male spade connector. Common sense (or lack of) told me that the male connector on the gauge is the 12v in. As if the connector fell off, a female would be covered and wouldnt short if it touched anything, as opposed to a male that would. Touched the sender and the gauge starts going up. I had the engine and the coolant fan on for a good twenty minutes so I was expecting just below halfway but no. It climbed and climbed until It maxed out. Has common sense let me down or is the gauge f*cked?

Next up is the engine oil. I believe it has to get up to temp before the engine oil is sent to the cooler, is that right? While the engine was on the oil pipes were cold. Is the spade connector next to the oil pump, is that a temp variable resistor or is it a temp switch?

The transmission cooler. There appears to be no sender anywhere. Does anyone know the cooler fitting thread type? Does the transmissions oil hoses usually come out the sump?

Whats the temp sensor on top of the engine usually plugged into? What temperature is it sensing exactly?

sensor on top of head is for egr not needed unless you want egr functioning,guage might not be matched to sender ,you may need correct guage or a resistor in the line ,oil pipes to cooler do have a thermostat in filter head ,oil sender is a switch which closes circuit to earth when pressure is low putting light on ,transmission wont have temp sensor unless its auto ,trans cooler pipes come from rear lhs of box

Superb post, thank you.

The gauge I've got could be from another model of LR. Infact, the truck had a v8 in it originally and this could be the gauge from that :doh:

I'll wire the oil light in since thats the case, cant hurt having it.

I should of added that it is an auto. I've read the sender located out with the box along one of the hoses. Being slightly customised I dont appear to have it.

oil temp for auto is usually rad end of cooler pipes

jamesmartin said:

oil temp for auto is usually rad end of cooler pipes

Click to expand...

Usually, but...



Thats the cooler on top of the radiator. I think i'll take the temp switch out that cooler and gently take a gas soldering iron to it and see if it switches the fan on. I'll run it for a good half an hour with the coolant fan on, see if the engine oil decides to start flowing. I'll also try wire the coolant gauge up the other way around and see if that does anything.

you wont have a box sender without the std pipes you could fit it in to box sump