please help 306 xld with crossed wire

Usual story... my 306 xld Mreg 120000ish on clock was working fine, until a
couple of days ago it went haywire, first thing to go was the clock,it kept
reseting itself, as did the radio, i banged the dash and pressed every
button in sight and noticed that the rear heated window button turned the
clock and radio off, next day or so the central locking intermittently
started to react in a "lazy way" as if the battery had low power, a few
days after when i turned the key the starter motor didnt do its thing(no
power to it) , so once again i hit the dash and pressed some buttons and
when i pressed the rear heated window button the clock came on and hey
presto the car started. now things have gone really downhill, i have no
central locking, radio ,clock, horn, starter motor, or courtesy lights
(however, the interior light works!?).

Ive checked all the fuses, relaysand changed the battery, also got the car
to start by touching a piece of wire from the battery to the starter motor
with the key in the second position . and since rigged up a temporary
switch to start it, but now Im lost.


I dont think its the imobilser as the fuel cut off solonoid opens to allow
the car to run, i would have expected that to stay shut but i may be wrong.
Why would so many seemingly unconnected electrical items go wrong at the
same time???


Please any suggestions no matter how simple or complex would be appreciated
very much,

 

Snipped.

From the varied symptoms I would suggest a loose earth somewhere, probably
in the vicinity of the dash but where exactly is another matter. Check the
connections to the fusebox at a first guess.

 

Well its sods law isn't it!!! You spend all day jacking the car up, pulling
off panels, scraping the skin off your knuckles, cleaning every earth and
connector in sight and still no progress, then my old man has a look-20mins
later he's fixed it!

Apparently, although I had done a visual check on each fuse and none had
blown, some had no power going into them, namely No 15(central locking
unit, remote control, courtesy light timer, pulse window winder unit.) and
No 25 (radio memory, clock, low engine speed carb, cooling relay energised
circuit, air conditioning.) So using a bit of wire, he fed power off the
cigar lighter into the back of fuse No 25 and instantly the clock and radio
turned on, then did the same to fuse No 15 and the interior light came on
(as did the clock and radio, must use the same feed further down the line),
tried the ignition that was ok and so was the central locking, so I must
have a loose or broken positive/live wire somewhere in the circuit, but as
another temporary fix we have bridged the live feed from fuse No 16(cigar
lighter + permanent feed) to Fuse No 15.

I just hope that this will last, and the situation doesn't get worse.

 

Oh yeh thanx for the sugestion Malc, you practicly hit the nail on the head.

 

wiring at ns behind the bumper has corroded this is where the feed to the
fuse box come through
it was part of a recall a few years ago but quite a few got missed out