Yep tried that Muddy with no luck.
We like fresh air Kristo but will give it a go to see what happens.
Rip'n the heater in the Patrol allways has hot water flowing through it. I know this because the shower does not need to have the heater on to heat up. Most modern cars are like that now. I've even thought about installing a valve in the heater circuit to stop hot water in that circuit. Worried about what that might do to the cooling system.
I'm going to have to pull it apart I'm gettin convinced of that. Burger... really dont want to.
A visit to Nissan to look at their diagrammes might be in order... keep you posted.
Keep the ideas coming, I've only been putting up with this for 18 months, I know i'm slack.
Cheers Macca