scoobyster

Hi All,

The ignition-on circuit in my MY95 has a mystery volt or two in it when switched off. Occasionally this goes through periods of upsetting the alarm since it thinks the ignition is being switched on while the alarm is armed, presumably this occurs when the voltage is higher and above a certain threshold. I think these periods tend to occur when the car is particularly damp – it first happened when I was staying with a relative and parking outside in the rain (usually garaged), and it’s happened in the last few days after a good session with the pressure washer to clear the salt. Sometimes the voltage goes right down to ~0.1v and causes no problems, but there’s always something there.

The voltage remains with the ignition switch disconnected so that can’t be the issue. Any suggestions where else could be introducing this? I guess the alarm (Clifford Concept 600) is a suspect but I don’t see how this could be impacted by outside damp since it’s inside the car (except for the siren and bonnet switch), also the voltage is still present when the main fuse to the alarm is pulled. I wondered about damp on the ignition leads causing a partial short, but I don’t see where these would get a permanent live source to short to. The battery does not seem to be losing charge.

Any ideas?

Cheers.

alcazar

iTrader: (2)

Try removing the negative lead from the battery and putting a multimeter set to volts in line with it, measure any current draw with everything off.

scoobyster

Had some fun with the multimeter - kept blowing fuses as the alarm goes off when the battery is reconnected (there is a system to pre warn the alarm that its battery is going to be deconnected, but I can't use it since the alarm won't arm with the mystery voltage in attendance, anyway...)

Eventually I used a second removable wire to bridge my earth strap and battery negative whilst sorting the alarm out, then put multimeter in parallel and finally removing my bridging wire to leave the multimeter alone. That showed me ~40mA draw with everything off and ~70-100mA with the immobiliser (not alarm) armed, with the higher figure being for when the alarm/immob LED was flashing on.

That sounds a bit high to me but not ridiculous, what do you think?

I've pulled the radio in case anything could be shorting in there - no change.

The last couple of days the problem is always there and the alarm always goes off as soon as it is armed. There is 1.75v in the ignition-on circuit when it should be off. If I connect the circuit to earth with the ammeter there is no current flow.

Also in the last couple of days I have notice a seemingly independent fault with the central locking. The alarm is setup to auto-lock the doors and unlock upon switching the ignition off. That is all happening, but I have noticed that the solenoid (in the driver's door at least, need to check the others) is fighting to push the lock locked throughout - it's not possible to unlock the door or pull the handle with a normal amount of force (I generally do this daily to unlock the garage before switching the ignition off).

I'm now wondering if the faults are related, since the central locking must have a permanent live it seems plausible. I've tried to disconnect everything I can see relating to the central locking in the drivers' door, but I've only disconnected the motor it would seem, since the central locking still works when operating that lock manually. My car was fitted with central locking as standard but not remote CL, hence the motor in the driver's door is retrofitted but the lock position sensing switch is not. Any ideas where to disconnect the lock switch? I guess the switch matters less though since that can't be affecting the driver's solenoid though. With the motor disconnected by 1.75v is still there.

I'm rambling rather here but thinking as I type. I guess this has got to point back to the alarm really. Any other suggestions welcomed though.

alcazar

iTrader: (2)

It does rather point at the alarm, doesn't it?

Can you get it to an installer?

scoobyster

Hi again.

In fact I think the sticky door lock was just down to the cold and not a problem with the solonoid, so scratch that.

I'd hoped to get through the holidays before addressing this but the fault has just got worse in the last day. The alarm system has now stopped responding at all and is deactivated. The car will start without unimmobilising but the fuel pump doesn't work beyond priming since the fuel pump immobiliser (which is wireless and so semi-independent) is not receiving an ok signal from the alarm, thus the car is undrivable.

The mystery ignition-on circuit voltage is still there and I have noticed that it increases to around 3v when the alarm's main fuse is removed and returns to it's 'normal' ~1.5v when it is replaced. I've tried pretty much every other fuse in the car too and the only others that affect anything are SB1 (30A) and SB5 (45A) in the engine bay fusebox, which have the same effect as the 5A alarm fuse in that the igniton-on circuit voltage increases.

The manual doesn't refer to the big chunky fuses, they're just labelled SB 1-5 inside the fusebox. I presume they are ignition related since they're high ratings, but anyone know the specifics of which does what?

Local Clifford guy is unavailable until new year so I'm a bit stuck at the moment. Clifford tech support is closed too but I've emailed someone I dealt with previously there so will hope for some contact.