[Wierd coolant temp sensor/gauge behaviour]

Thanks for the replies and yeah, with the T shaped connector I ment the prongs on the CTS.

I really only have 2 instead of 4 items (there are so many small differences to american models which makes research really frustrating sometimes). My guess is that the singe prong connector on my intake is equal to item #1 in the image admin_JAinsworth posted. I think I lead myself on a false path by thinking that the CTS is connected to the temperature gauge in the dash.

I already replaced sensor #1. I will however compare its resitance to the old one in some hot water.

[Wierd coolant temp sensor/gauge behaviour]

Im figuring out a european 88 narrow body and stumbled upon a wierd coolant gauge behaviour.

Right below the thermostat housing on the intake manifold are 2 temp sensors:

• 1 acutal sensor with a T shaped connector
• 1 temp switch with just a ground connection

 

Here is what I dont understand:

The coolant temp gauge needle only moves if the temp switch is closed. If the switch is closed, the temp gauge needle instantly jumps as high as it goes. Even if the engine is stone cold and I short the switch to ground, the same behaviour occours. 

Im pretty certain that the T shaped connector is for the coolant temp but Im beginning to doubt that. I will install an aftermarket temerature gauge just to be on the save side because I know that too much heat has some pretty bad effects ion these engines.

Can someone explain whats going on?