1996 Polo blowing fuse 21 (interior lights and locking)

[GavHT]

This is driving me round the bend....

Our 1996 1.4 CL 5-door Polo, as much as I love her, is blowing fuse 21 (interior lights, central locking, cigarette lighter, clock) on an intermittent basis. What I have done so far:

- checked all cabling into front doors (found and repaired 2 broken wires and 6 with fractured insulation - glad I checked )

- removed central locking pump and cleaned up dirty circuit board and connectors

- disconnected boot light (last ditch attempt to fix!)

- replaced 15A fuse with 20A fuse (against all the rules I know... it blew)

Because the 20A fuse blew this suggests to me a short somewhere.
The fuse blows without any particular pattern (open car, get in, alls fine, drive, reach destination, fuse is blown!!).

Any ideas

Cheers.

[GavHT]

bump

[tech1]

Hi Gav this will take a while to pinpoint.best off removing fuse in question,see what is now inop.refit fuse but disconnect 1 thing at a time to see what is blowing fuse,after short run as you described.once found eg interior light,check for short circuit on live wire whilst moving wire.sorry this is the only way you will find fault...