TDI won't start: Relay 219 clicking?

hello
I removed the auxiliary heater with its wiring harness from my 'old' A4 TDI (81 kW, 11/97), and now it won't start, it doesn't pre-glow, and relay 219 is clicking rapidly. Does anyone have any idea where the problem might be?
After upgrading the heating system with new water and diesel connections (and bleeding them), it ran fine. Then came the problem with the wiring harness, and that was it.
In my opinion, I have properly insulated everything and reconnected all the connections.
Is there a wiring diagram available? Or does anyone know where I can find one?
hello michael