• Hi Guest!
    If you appreciate British Car Forum and our 25 years of supporting British car enthusiasts with technical and anicdotal information, collected from our thousands of great members, please support us with a low-cost subscription. You can become a supporting member for less than the dues of most car clubs.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

Help! I give up!

Share this page

judow

judow

Darth Vader - R.I.P
Offline
:banana: Please to tell me what a "passive alarm system" is. It seems that on my 96 XJS my battery was deader than a door knob. It seems that I haven't started Onslow in almost 3 weeks and when I went to take him to the garage because the A/C wasn't working, he refused to even gurgle. After using the charger, he finally started. The shop made a comment that the 'passive alarm system' was on and that is what drained the battery. Apparently the passive system can be shut off by reprograming the computer module. I guess this will be done when I get the new hoses and whatever else including the freon charge to fix the A/C - and for only $800.00. Oh well, enough complaining. I just what to know what the heck this 'passive alarm system' is. I would have asked but being female I simply nodded as though I knew what he was talking about it.

Fact: I haven't a clue! Husband will be looking for an explanation though.

I really would like to sound like I know what I am talking about.

:thankyousign:
 
Most cars with alarms have this supposedly passive system. It is actually live and draws current even when not used. If the car sits for more than a few days it can draw down the battery enough to keep it from starting. Therefore, car must be driven a couple times a week or a trickle charger will have to be installed. Sometimes you can unhook the fuse to the system, but that too can cause a no start. Never owned a Jag with an alarm, but hated them when they came to the shop for repair. Anytime you unhooked the battery it went off. I have a Range Rover that really takes the power out of the battery if it isn't driven regularly.
 
if that is what "Passive" means, then I wonder what "Active" means. Actually I don't want to know. I hate car alarms. They are useless. I bet every neighborhood has one of those dumb Japanese car alarms that go off by themselves if an insect lands on the car's roof at 3:00 am. The longest 5 minutes worth of dumb noises and then it resets itself only to do it again?

If it was MY car, it would have been disabled already and forever.

Ex
 
Exotexs said:
if that is what "Passive" means, then I wonder what "Active" means. Actually I don't want to know. I hate car alarms. They are useless. I bet every neighborhood has one of those dumb Japanese car alarms that go off by themselves if an insect lands on the car's roof at 3:00 am. The longest 5 minutes worth of dumb noises and then it resets itself only to do it again?

If it was MY car, it would have been disabled already and forever.

Ex
Click to expand...

What you just described is an "active" alarm..... :wink:

"Passive" does not activate unless a door, the boot or the bonnet are opened.
 
:winner1: me. Thanks for the info. The Jag dealership said that they would program the alarm system to not do this. Larry, Steve, you all are quite correct when you say that I need to drive Onslow at least weekly as this is exactly what happened. What I had done was detail the car and of course opened the door(s), boot and bonnet and never did drive it. Until I get the problem dealt with, I'll just have to find excuses to go tooling.

Thanks for the info. I think I now have an understanding of this 'passive alarm system' thing.
 
Back
Top