ZD30 engine control fuse blowing

Hey guys, I recently bought a 2008 ZD30 CRD patrol and am having problems with the engine control fuse blowing. I have never had the fuse blow whilst day to day driving but for some reason whenever off road (both 2wd and 4wd) the 20a engine control fuse blows. It seems like it's whenever the car is under load it cuts out and stalls as the fuse blows. Sometimes the car just cuts out the throttle and I have to put the clutch in to save it. Just wondering if anyone would have some advice as to why the fuse is blowing? The car has been to 2 auto electricians and they have checked the harness all the way to the ECU and haven't found any issue. What could be the cause? I have a lift pump on the way to see if maybe the car isn't getting enough fuel and is blowing the fuse as a safety measure?

It sounds like a short in the wiring harness that is only a short when bouncing around ( like 4wdriving ).

The Autoelec is looking in the same place i would look too.

There is no more load running around in 4wd as there would be when you drive the car running around town up and down hills, etc.

If you can't find the problem any other way, and this includes visual inspection and insulation resistance testing, I would be moving the harnesses up and down ( wiggle it around as much as you can with the ignition on while you are parked up to see if it blows the fuse whilst you are playing around with it. You should be able to move the harness around just as much as it would when 4wdriving .

In my humble opinion, the lift pump won't solve this issue.

Thanks for the reply mate, the auto electrician has tried wiggling the harness with the ignition on and they never found an issue. Has me completely stumped