Hello,

I have a 92 300D and I’m doing a conversion with a Greases Car Kit. I'm trying to understand the best place to pull hot coolant and return the cooler stuff. I'm worried about the flow being cut off through the hose going to the cabin heater when the heat controller is not calling for heat.

The progression I see is

1. out of the back of the engine
2. into second external pump (The first pump would be the main water pump in the engine.)
3. out of pump
4. split of between cabin heat exchanger and windshield wiper fluid by the fuse box
5. into cabin heat exchanger
6. out of the cabin heater through two hoses
7. two hose converge into one valve by the battery
8. valve goes into main water pump

Extra - the windshield wiper fluid goes back under the engine to the main return from radiator.

Should I connect coming out of the engine and before the second pump for the hot?
Then connect the return after the Y valve on the return (near the battery)?
Does the second pump always run? Should I connect after it?

Thanks,
Jay