BA 4 heaters no longer have a fuel overflow pipe. Stocks of previous heaters can be used up.
Both pictures show glow-spark plug connectors which have been damaged by arcing.
In Fig. 1 a small hole can be seen in the connector. It was caused by arcing between the glow-spark plug connector and the low voltage terminal.
Fig. 2 shows a connector which has a hole burnt in it due to arcing between the copper core of the wire and the vehicle body.
These defects can cause ignition trouble and actuate the safety switch during the start-up process or when the heater is regulating.