Where does the ground for the thermotime switch goes?

Hello everybody! I almost figure out my problem with my csv and thermotime switch. When i add an extra ground cable to the green/White cable it works fine. When i dont use extra ground it doesnt work.

I need to help to find out where does the green/White cable go? Where is it earthed? I cant fint it…

Would love if someone helped me out.
Cheers

You can tie it to any convenient ground point Ie: Water outlet flange bolt, Alternator Case nut, Valve cover.

Yes i know that. But doent the green/White cable goes anywhere? Like into the fusebox?
Would like it to work as it should.

Could it be that the thermotime is grounded where its bolted?

Depends on who makes it.  In VW electrics, Brown wires are ground.  Any other color goes back to the fuse panel or controller.

If the manufacturer of things has a Isolated circuit design then you will have two to 3 wires out of a Seding unit and one of them is usually ground.  

IE: my 90's cabbies used a ground wire to the 2 sensors for Water temps, one was coolant temp to gauge and one was coolant temp for the "puter".  Since the flanges were plastic, they needed a separate Ground. even the 16v CTS sensor had separate grounds for it.  

Ground is Brown…

Yes i know Brown is ground here aswell. But doesnt the thermotime and csv have it own circut? When I read on other forums for this is thay the green/White is ground and the black goes down to the starter 15a pin.
Should i ground the green/white extra? Then it works aa it should
Or is there a Brown ground AT the fusebox for this?

Thanks for the answers

The red/ black should have power on it when cranking and powers a heater in the thermo time switch.
The green/ white is not an earth, it goes back to the cold start valve. The earth is supplied through the metal body of the thermo time switch, through the engine and back to the battery. If the switch isn't switching to ground it's either broken, not grounded to the engine properly or the coolant is not cold enough. Remember if the engine coolant is above a certain temperature you do not need the cold start

Another thought, make sure it is a thermo time switch and not some other sensor put in by mistake.

Thank you so much for a good answer. I think my thermotime is broken then or faulty. Ive resd that t
If the engine is less the. 30c it should work?

When I turn the key over with a multimeter plugged it just shows like 0.89-0.95. If i add extra earth to the green/White it shows 12v for like a sec as it should.
Then i guess that its not enough earth?
I bought one from autodoc. A copy.

Which one should i buy? Brand? Got any tips?

/Andreas

Don't know specifics as I have never tested one or had that on my 90's Cabbies or my 81 Diesel.

I do have a few decades of VW electrics, and almost 50 years electrics as living.

Yes okay. I Will try by buy a new thermotime from bosch. I saw they were pretty expensive... that one ive got is a cheap copy. I think its faulty

You can test it by putting it in the fridge for a bit, and then in hot water.
First test would be to measure the resistance across the  red/black terminal and the body - this will be the resistance of the heater coil. Don't know what it should be but it shouldn't be very high or 0. If it measures something then put it in the fridge for a bit, then measure continuity (beep) across the green/white terminal and the body - at this point it should be 0 or a beep on your multimeter (switch is closed). Stick it in some hot water and repeat test, this time you should be open circuit (switch open).
The heater coil is desined to open the switch after a period of time so that you don't have the CSV firing all the time.
When it is in situ you should measure the resistance between the body and battery -ve. This should be very low and indicates a good earth. Probably also worth checking engine block to -ve to make sure that is good first.
Might just be a case of cleaning the mating face of the thermotime switch to the output flange, might just be a build up of crud/scale from any water.
Bit of 400 grit on a flat block to clean it up.

Yes! Thanks 4 the advice. Im godnatt try buy a new one. I think i bought a weong one. I Will Come back with more info