Yeah. I wired them up exactly as if they were the main relay. I opened the old main relay up, and you can can see the way its supposed to work. 2 terminals for the coil. And then 4 terminals for the 2 pairs of contacts. It seams both contacts operate exactly the same. But are kept seperate for some reason. It would seam the contacts that operate the heater circuits stay on while the main relay is on. And I cant see how they could turn off without turning off the relay. They must be controlled and monitored on the negative side of the heaters by the
ECU. Hence how it is able to detect a fault and log a code.
My only concern now is the relay is actually switched by the
ECU. It controls the negative side of the coil. The original main relay coil is 80 ohm. My new relays are 90 ohm each. Which means together they will pull nearly double the current on the ECUs trigger for them. Hopefully it will be fine.
The old main relay didnt appear to have any diode/resistor protection against self induced spikes when the coil field collapses. Which i thought was odd for a
ECU switched relay.
I am an auto electrician BTW.