Dead electrics

[J_T]

Hi all,

I picked up my first FD on Saturday and enjoyed the drive back from Oxford to South London.

I put the car on the drive and turned off (after period of idling to let turbos cool) and when I went to restart her all the electrics are dead.

Nothing at all is working including horn - I can\'t find a fuse for the horn in the manual, does it have one?

As it is all electrics including the horn that I don\'t believe has a fuse I\'m thinking it could be an old immobiliser kicking in for some reason.  I thought this could be due to the slope on the drive triggering a tilt sensor but I\'ve just put her in the road and no change.  Does this sound feasible to anyone here?

There are remnants of an old security system that I\'m getting removed when the new one goes in.  It\'s supposed to be being installed this afternoon so is there anything else I can check first?

I\'ll get a multimeter on the battery in a minute, what reading should I be getting for a battery in good condition?

Thanks,
Jon

[J_T]

Just checked the battery - 12.74V.  That should be fine right?

Looked at the two fuse boxes while I was there and can\'t see any that have gone.

[trotter]

As far as the battery voltage goes you need anything over 12V to crank, but even if it was dying you\'d get some noise.

Ive had a random problem recently that was almost identical to yours. Turn ignition key to pos 2 and everything works, soon as i go to crank everything dies. I sorted it each time by touching the positive terminal on the battery and hearing the F-100 relay click. Turns out, the connection to the battery was crap, once i\'d cleaned it and tightened eveything up no more problems.

[Bobbit]

Yep, mine would do this from time to time, the battery connection was the issue, to fix it I tightened up the connection and carefully hammered a nail between the bat and connection, this tightened it all up nicely. eventually I just bought a new battery. Or you could use tin foil, fold it up, put it on the bat terminal, add connector and tighten.

[J_T]

Thanks for the replies.

The alarm engineer identified the same issue with a dodgy mounting where the first fuse box meets the positive terminal.

Closer inspection also revealed a bodged battery tray which will need sorting.

Jon