Also the clignoteur is sometimes restorable.
On the picture to the left this clignoteur did work more.
The contact where the heat wire is mounted to was to var open and was oxidized.
After the contact is cleaned the contact points distance schould be about 1 mm.
Than you need to test to see if it works again.
The Daf 600 has a special clignoteur.
The contact of the indicator is completely separated.

This is the reason why there are 4 contacts.

To know:

15X = The + 6volt black wire at the Daf 600
54L = to turn switch the green wire.
K1&K2 (P1&P2) control indicater red or yellow.
This two wires doesn't make a different how it's conected.

  The test lamp is a 6volt 21 + 5  Watt
  total 26 Watt.

  Normal 2 X 15 Watt total 30 Watt