1994 Ford Escort battery not charging

Electrical problem
1994 Ford Escort Manual van miles

Hi,
i have a 1994 ford escort van 1.8 diesel. The problem is that it wont charge the battery. I have replaced the battery and the alternator but still no luck. I have checked all the fuses and they seem ok. I have traced all the wires for brakes/corrosion but they all seem ok too. All the earthing point are ok. When I run a meter across the battery when its running the battery slowly dies. When I put a meter across the altornator is reads 0.01v. I suspect its a wireing problem but I dont know where else to look. Also it will start with a tow rope of if I leave it connected to my other car for about half hour.