Well weve ticked off everything I reckon bar the aerial itself, if I recall the snow flakes have a splitter which you said you had swapped out, so that a lead goes to the vertical and horizontal sections so if theres 12v at the terminals of the splitter then its narrowed the fault down to the aerial itself................
Looked at my transmitter info and at Rouse Hill the tower is about 30km away, in a ESE direction moderate coverage BUT an elevation profile shows a hill in between so unless your location is higher, then a van reception may not be much chop, unless you have had reception in this position before of course, I'm just using Rouse Hill centre as a pin point , if you haven't had signal from there before then don't go for a new set up...... I use the MSwitch site on a laptop to locate transmitters, shows all information for the location including an elevation profile.
Looked at my transmitter info and at Rouse Hill the tower is about 30km away, in a ESE direction moderate coverage BUT an elevation profile shows a hill in between so unless your location is higher, then a van reception may not be much chop, unless you have had reception in this position before of course, I'm just using Rouse Hill centre as a pin point , if you haven't had signal from there before then don't go for a new set up...... I use the MSwitch site on a laptop to locate transmitters, shows all information for the location including an elevation profile.