Sorry been a while guys, not divorced yet. Lady J is performing well. Changed the exhaust today. Now sound like a jag and not a f150 deisel. Now just have fix some minor issues. Return line to left hand tank not working. Heater not working, and finally i have noticed that the aircon stays on windscreen all the time. But all in good time. Thanks guys to those have helped with ideas.

 

Sorry Matt, no answers for you with your issues. But good see you back on the forums.

 

If that's the only aspect of the changeover system that isn't working properly then I suspect you simply have a dead return valve. This is the valve mounted behind the left rear wheel.





Does the heater valve operate? Look at the valve....it has an external operating arm....while a helper operates the temp control knob from cold to hot



Lots of possibilities. All all four system fuses OK?

When you switch modes or temp settings do you hear a faint whir from behind the dash?

Cheers
DD