If it is a DC01/ DC04 the not very good plastic cable dyson use consistently breaks. Disconnect from mains and you will probably need a tork drive bit to fit the cover panel. There are two internal routes the pos and neg wires take , and it is fiddly to connect properly the wires to the on / off switch ( pos ) and the neg side conector. With additional fingers it is easier.
Try to get a good 15 amp cable , ( rubber ) to your desired length , mine has come from a Henry that blew its motor ( the third blown one I have had ! ) and replace the dyson mains cable completely.
whyperion
May 2009
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