Hi all. I'm looking for help with the security system on my '90 convertible.



When I got it out this year, it started acting wierd. I start it, and everything's good for about 30-60 sec, then the security system goes off. Lights on, horn on. Turning the ignition off does not turn off the alarm. Disconnecting the battery shuts everything off, reconnecting it is ok, but if I start the car, after a little while the alarm goes off again.



Anybody heard of this problem? Hints on debugging it? I never did get shop manuals for this car, maybe now's the time: Anybody got recommendations on a docset comprehensive enough to cover this kind of issue?



Thanks in advance...

 

when it started acting up on my 88 i just disconnected the alarms box

 

Is that the unit down in the left kick panel? Is there a plug I can just disconnect? TIA...

 

Bump.



Still trying to debug this. I looked in my haynes manual, and it describes on page 270 the "theft deterrent control unit" next to the speaker assembly behind the glove box. I pulled out the glove box, and dug around in there, but there's no sign of a unit there which looks like what the manual calls for. however, there's also no speaker behind that grille, so I wonder how well this manual covers the convertible, as opposed to the hardtop.



Anybody got any better information about where, in my car, the theft deterrent box is, so I can disable it? Thanks in advance....

 

i heard you had to stick the key in the trunk to turn it off but yank that out cause i heard it causes nothing but problems

 

My fondest wish is to yank it out. If someone can tell me where it is, that would make it easier :-)

 

hmmm i heard its in the engine bay but idk it could switch between coupe vs vert and s4 to s5

 

Any idea where in engine bay? I looked around on the firewall but didn't see anything that looked likely. The manual sez it's under the glovebox, but that appears to be in error.



What's s4 vs s5?

 

it should be on the driver side (left) and by the fire wall from what i hear and s4 vs s5 is the year if you own a 86-88 you are s4 89-91 you are s5

 

Ok, per the first post, I'm an s5.



I see two small units on the driver side fender, right up by the firewall, just outside of the clutch cyl. One's about 3cm x 3cm by 8cm, one's about 3x6x8. Both have connectors coming out the bottom. They're in about the right place to be the main fuel injection relay, according to my haynes book, but since that's clearly not accurate, perhaps one of those is the beast I'm looking for? There's nothing else in the vicinity which looks like a likely candidate.