Bongo Fury

Freda has remote central locking. If I unlock her and get and turn the key within 15-20 seconds, the glowplug light will come on, then go out as normal when the key can can be turned the final bit and off she'll go. If the key is turned the last bit AFTER the 15/20 seconds has elapsed, nothing will happen until the unlock button on the zapper is pressed. Then the glow plug light will come on as normal. This morning I needed to press the unlock button on the zapper, but the glowplug light didn't come on. I don't think it's the zapper because the spare didn't work either. Is there a fuse which may have blown? All was fine yesterday. Suggestions welcome.

There is a fusible link in the supply to the Glowplugs;

Spares available from the shop if it has blown, but normally there is a reason for them blowing, like some one having worked on the engine ...