Hello all, my 98 xjr has developed an issue I found funny but is now annoying
started as key out and car still ran, open n close driver door and car would shut off
recently the ignition turns on by its self without key present and the car then won’t start, and the alarm goes off which is very annoying
I’ve got to lock unlock with the door then key in the ignition and it might work
any help is appreciated

 

Damaged wiring in near the lock where the key goes? Rodent-caused?

 

Possible sluggish lock window/barrel on the ignition - some sort of lock lube like graphite might free it up? When you pull the key out there should be an audible click as the lock window shuts. Graphite cover the key and insert it in and out a few times, along with puffing it into the mechanism lightly. With the battery off you can do this without causing more problems to the security system. If that doesn't get it back online it's most likely a wiring issue on the back of the ignition barrel as V8 suggested...

 

don’t think it’s rodent as far is used every single day and not in rodent area, however car has slight rust hole in wheel arch not sure if moisture could be causing

 

would that be causing the alarm to go off as well you reckon?

 

One day, after my 1999 Super V8 had been parked (locked) for a few days, when I came to the car I heard some humming sound coming from the engine compartment. I found out that the Charge Cooler pump was running and the Throttle Body was energised and humming. Turned out to be caused by faulty alarm siren. Something went wrong with its electronics allowing the current from the siren's battery to flow back into the loom and activate a couple of relays which switched the pump and the TB on. I just unpluged the siren and had no more issues. And the car still has alarm sound from the car horn.