SLROC Forum

Hi new to all this forum stuff.

I just bought a td5 defender at the weekend and one thing thats odd since i bought it was the temp gauge sits midway after start up then shifts to cold as the heater heats up. Phoned the boy who had it before me and he told me it had a new ECU , and the ecu temp gauge was programmed wrong. Does anyone know the resistance readings from the temperature sensor (thermistor) . I got the information from the online workshop manual that the resistance decreases as the engine heats up. The workshop manual doesn't give any meter readings . Does anyone know the values or readings expected with a multi meter .

It's got the wrong sender in it.  Get a Td5 one!

Thr temp sender is fine, they are the same in disco & defender td5's

I am 90% sure that it has a disco ecu in it as when they are put on a defender the guage reads back to front,

I have a disco 2 td5 in my buggy with a defender loom, defender dash & the ecu is programmed for a defender & it all works fine

You need your ecu programed to a defender & make sure the ecu is well earthed as that can also cause a similar problem

Yes I think that's the case too: the Disco and Defender td5 ECUs run the water temperature gauge in opposite directions.

My Ibex had a similar feature.  The ECU was a NNN120 type (later programmable one) and I was told by the seller that it read 'backwards' because it had a Discovery ECU, although the donor car was a Defender. . .  Years previously I had put a Disco II NNN120 ECU in my 110 Tomb Raider and the temp gauge read fine (although it was programmed to tell it it was now a Defender).  So I thought that it must have had a Disco II temp sender in it.  I'd be interested to know the outcome.

cheers for the quick replies . Phoned the guy who did the ecu and he says the software he had was a discovery one but now has defender software but he won't touch it till december as he's fully booked .

 I was wondering can i change the polarity of the gauge by swapping the crimped connections in the multi plug in the temp gauge, until i get it reprogrammed. Another issue now in my head is it has been sitting in the blue have i cooked the engine or does the ecu know its cooking and go into limp mode ? I have also found a leak in the radiator so got one on order could it just be this thats why it to sits in the blue (defender) but its really in the red . Don't think the head gasket has went as there is no oil in the coolant or coolant in the oil , no white smoke. Left the land rover at home till

Swapping the leads won't work.

Getting to the blue is just normal running temp the other way round isn't it?  Gauge starts in the middle not the top of the red doesn't it.

I've only seen it once start in the red once and thats when alarm bells started ringing . I just bought the car at the weekend. so its laid up until i have fixed it .