Electrical problem on Mk3 flat smiley

[kermu]

Hi,

A fuse recently blew in when I plugged a tyre pump into the 12v cigarette lighter plug. Whenever I stick another fuse in now, that fuse now INSTANTLY blows when it's plugged in (even fuses with larger amp rating). The fuse also controls interior lights

In the attached Pic, the fuse socket is # 21

Please does anyone have any idea how I can start troubleshooting this, or what the issue could be?


Many thanks

[loot]

My only guess is the original fuse held long enough for wires to short somewhere so now you have permanent short so during the fuse closes the circuit and pops.

F21 is designated as heated glass, does it have multiple purposes? You would have only blown the 12v cigarette lighter socket fuse or related.

More info needed.

Did you blow the cig society fuse? Is the cig socket a factory connection or aftermarket connection added?
Is it added to the f21 circuit?
Is the wiring all correct and tidy?
I'd expect the loom to be all chopped and spliced all over the place since original?

Anyway, circuit diagram or trace the wires to the fault point. You can use a lamp tester and multimeter to help you.

[Altransit]

It's probably the socket itself, they're known to short out with the internal contacts. Try pulling the plug off the back of the socket, and see if the fuse still blows

You can buy new sockets on ebay, if it is faulty

[kermu]

Thats for both comments. I suspect the latter - 12v ciggy socket shorted in the back - I'll check that first! that specific fuse (in my van anyway), covers the 12v Ciggy and internal lights.