B200K Temperature Sensor Wiring
 

Shortly before taking my car off the road before its MoT expiring in late November I noticed that my temperature gauge had dropped to 'cold' and the red coolant warning light was on. The car showed no signs of overheating and no loss of coolant, cold hoses or cold air through the vents. I thought this would be the coolant temperature sensor below no. 2 cylinder on the intake manifold side, so I ordered one up. Only when I went to fit it today did I discover that a) I've ordered the wrong one as the one on my car is a spade connector, and b) the wiring itself was actually disconnected and the end of the plug was broken, likely due to the heat exposure and 33 year old plastic. It seemed a bit of a 'stretch' to the coolant temp sensor but it wouldn't plug back in anyway due to it being broken. Do I stand a chance of getting one of these to replace it? And if so, where would it plug in at the other end? A Scottish winter day today meant I didn't spend too long under the bonnet to investigate. Thanks in advance.

Have you got a photo? I can't picture what you're saying properly.

I'll try and get one today, it's rather buried under the inlet manifold but will see what I can do!

Been trying to upload the pic last night but to no success, I may try another way but a pic is coming!

I think he's looking for the wiring colour code for the temp guage sensor Luke, sounds like the sensor he ordered was the ECU sensor for EFi models and not the guage one.

Ah I see, sounds like I have the wrong sensor then.

If anyone wants an EFI sensor then let me know!

What's the make and part number of the sensor you've got? Also which car/year/fueling is it?

I'll check the invoice for the part number etc, the pin is definitely different to the one on my car. My car is a 1988 360 GLE with the B200K, and it's the incorrect part. As I say, the wiring on my car is knackered it seems, so the sensor may be fine. Sensor I bought has a blue electrical connector at the end.

Thanks,

Joseph

That's the carb engine then? Is there only one terminal on the sensor you bought? Can you put a photo of the strange blue connector up?

What you say is correct but given the ECU temp sensor is 2500 +/-12% at 20C, 0.04 Ohms difference in the wires to/from it won't make a significant amount of difference. Even at 80C it's in the order of 290-364 Ohms so again, 0.04 Ohms won't make any real difference.

Simple fact is the supplied sensor was for the engine management ECUs, it should have been for the instrument in the dash which uses a different sensor.

Also the broken wiring to the gauge sensor would give exactly the symptoms the OP described.