And are there two separate radiators (heat exchangers)? i.e., where does the electronics cooling circuit dump its excess heat?

 

As I understand it there ARE two separate heat exhangers... the electronics one is smaller.

There wouldn't be much use for two reservoirs into the same system would there? Fluid flows to the lowest level. The level would be the same in both at all times if they were connected so a second one would serve no purpose that I can think of. Mine are at different levels.

Just verified pg 280 of the '06 Owners manual. "Your vehicle is equipped with two separate coolant systems..." and on page 281 " The two systems us the same coolant and operate similarly, with the Motor and Electronics system generally operating at a lower temperature and pressure"

They use the same kind of coolant but are separate systems. Otherwise you couldn't have two different pressures maintained. Well I suppose its POSSIBLE you could have two pressures, but its certainly not likely.

 

Thanks for looking that up - I'm amazed at the complexity.

 

An easy way to tell is to check the temp when cold. It should match the outside air temperature. I believe it is in degrees F, but I would want to verify the scale is correct on the SGII prior to betting my vehilcle on it. Just my crabby opinion.