D1 alarm going off

Tugela

Well-known member
May 21, 2007
4,756
563
Seattle
Right before I left for a 2-week trip my 98 D1 alarm started going off unprovoked. Never had this problem before. I didn't have the time to investigate and haven't yet dug into it since I'm still jet lagged, but where should I start? Historical threads don't cast much light upon random alarm issues. Possible relevant context:

  • Battery is 5 or 6 years old, installed by previous owner, not a high quality model. I need to test the voltage.
  • Engine is occasionally sluggish to start. Also suggestive of battery issues.
  • New alternator.
  • Wife dumped a half box of plastic toothpicks down the back of the dash behind the steering column. Don't ask how that happened, I have no idea. Would a bunch of loose debris mess with any of the electrics?

What should I be looking for? Electrics is not my strong suit. Until I figure this out I throw the aftermarket battery isolator switch when leaving it parked to avoid annoying my neighbors.
 

gimebakmybulits

Well-known member
Dec 11, 2013
1,067
85
Pasadena
Right before I left for a 2-week trip my 98 D1 alarm started going off unprovoked. Never had this problem before. I didn't have the time to investigate and haven't yet dug into it since I'm still jet lagged, but where should I start? Historical threads don't cast much light upon random alarm issues. Possible relevant context:

  • Battery is 5 or 6 years old, installed by previous owner, not a high quality model. I need to test the voltage.
  • Engine is occasionally sluggish to start. Also suggestive of battery issues.
  • New alternator.
  • Wife dumped a half box of plastic toothpicks down the back of the dash behind the steering column. Don't ask how that happened, I have no idea. Would a bunch of loose debris mess with any of the electrics?

What should I be looking for? Electrics is not my strong suit. Until I figure this out I throw the aftermarket battery isolator switch when leaving it parked to avoid annoying my neighbors.
My 98 started doing that after the hood switch fell apart, although that may just be coincidence. I just do the key in the door lock to the right (to the left) for 10 seconds to disable the alarm.
ETA- It's turn and hold the key in the door to the left (not right)
 
Last edited:

4Runner

Well-known member
May 24, 2007
662
111
Boise Idaho
X2 on the hood switch. When I have alarm issues, I undo the grill and disconnect the horns. That way you can trouble shoot in peace. Or you can just go for it. Arm your alarm the move to your hood and press on it in different places and also pull up on it and see what happens. You should not be able to activate the hood switch while the hood is latched. The switch might just be out of adjustment or more likely, the switch is falling apart internally. If it’s bad you can just bypass the switch or replace it if you like. But really any flakey door switch can cause that problem. The less thorough way is to go to each door open one at a time and cycle the switch a few times watching to see your interior lights go on and off at the appropriate times. I don’t have any experience with the ultrasonic portion of the alarm if you have that option. Good luck. Hopefully it’s just a switch.
 

jastutte

Well-known member
Nov 10, 2009
465
75
Right before I left for a 2-week trip my 98 D1 alarm started going off unprovoked. Never had this problem before. I didn't have the time to investigate and haven't yet dug into it since I'm still jet lagged, but where should I start? Historical threads don't cast much light upon random alarm issues. Possible relevant context:

  • Battery is 5 or 6 years old, installed by previous owner, not a high quality model. I need to test the voltage.
  • Engine is occasionally sluggish to start. Also suggestive of battery issues.
  • New alternator.
  • Wife dumped a half box of plastic toothpicks down the back of the dash behind the steering column. Don't ask how that happened, I have no idea. Would a bunch of loose debris mess with any of the electrics?

What should I be looking for? Electrics is not my strong suit. Until I figure this out I throw the aftermarket battery isolator switch when leaving it parked to avoid annoying my neighbors.
on my '96 the issues was lazy door lock actuators. one, i can't remember which one, would not lock in time and eventually at all. i had to stop locking the truck using the FOB.
 

discostew

Well-known member
Sep 14, 2010
7,713
1,016
Northern Illinois
I know T4s in working condition are hard to find. I really don't have access to one right now. But this is a simple problem to diagnose with the right equipment. The car keeps track of alarm trigger history. You get a list of the last triggers. Could be a hood switch or a door latch. Your just guessing without the trigger history.
 

Tugela

Well-known member
May 21, 2007
4,756
563
Seattle
I know T4s in working condition are hard to find. I really don't have access to one right now. But this is a simple problem to diagnose with the right equipment. The car keeps track of alarm trigger history. You get a list of the last triggers. Could be a hood switch or a door latch. Your just guessing without the trigger history.

This is good information to know, but then I wonder why LR doesn't make this kind of data easier for owners to access. A local shop has T4, I just need to decide to pay for the hour of labor.
 

Tugela

Well-known member
May 21, 2007
4,756
563
Seattle
on my '96 the issues was lazy door lock actuators. one, i can't remember which one, would not lock in time and eventually at all. i had to stop locking the truck using the FOB.

This appears to be the most promising lead. Upon further observation I notice that the front driver's door plunger doesn't go down all the way when using the central locking. I think I might have a new actuator in my parts bin. Any idea if they are the same for all the doors? Part of me thinks "LR was so cheap they would use the same part in all 5 doors" and part of me thinks "LR doesn't follow any logic and might have different actuators for different doors."