Defender electrics..HELP please

Had a day on the defender (1991 200 TDi 110). Fitted 2nd hand bull bar (bit of knocking involved) fitted 2nd hand set of column switches (all tested amd worked), messed with wiper motor and OK. Finaly doing some stuff with cigarette lighter and all of a sudden found all power gone, Checked every inside fuse and all Ok. Looked at the various (dead end) connections behind the cigarette llighter panel thinking something loose there but they must all be there for things I dont have. All of a sudden "click" from the fuse box area and eveything back on. Tidied up but then all off again! Battery fine, over 12V. Checked the big brown lead going into the junction box that the glow plug leads come from and good 12volts there.
When power off there is none to inside light or hazards so it cant be ignition switch. Driving me nuts. Is there a big fuse I am missing? Or what else may it be please!!

i know the 300 tdis have a fuse box in the engine bay on the left near the heater blower . has a cover on it and 3 or 4 large fues inside check it out your 200 may have the same .

Interesting, this could be what's wrong with some of the switches on my lannie.
Have you any pictures of this fusebox.
My useless Haynes manual (well in this instance ) only has the TD5 layout pics

if its not a fuse then its more than likely a bad earth connection, maybe you didnt reconnect something tightly afterwards?

your right sounds like something loose.when a fuse is gone its gone

Thought about this and as it was total faliure (other than glow plugs) thought it must be main supply to starter (where other power is taken from). (Haynes shows one dorect leads to glow plugs and this feeds radio also.) Checked starter this morningand it was loose. All OK now. (how the hell do you get to the starter!)

is there not a power serg relay at the back of the dash on the 200 may be that with it comeing back on