UAE_Z28

iTrader: (14)

Hello,

Whenever I open the driver's door, the passenger door unlocks, I can even hear the car unlocking as if someone pressed the unlock key. My car is a 98 Z28.

My buddy has a 98 Z28 as well but he doesn't have this feature. What is the reason behind this? is this a stock feature?

michaelhawk

That's not a feature. I would look into the problem being with the BCM. They are known to have solder joints go weak, break and do strange things.


https://ls1tech.com/forums/general-m...blems-fix.html

Nathan C

If you press the unlock button once on the remote, it will unlock the drivers door. If you press it twice, it should unlock both doors. If that isn't whats happening, something is wrong.

1999nbmZ

You could also have some damage to the wiring inside the door. If the lock/unlock wires are exposed and contacting something else, that could cause your issues. Not sure if I can walk you through diagnosing online.

I would start by figuring out if it happens when the door swings, or when you are pulling one of the handles to open it.

WhiteBird00

iTrader: (4)

If you're referring to unlocking when using the remote, there is a common and simple modification that changes the factory function so that both doors unlock with the first press of the unlock button instead of requiring two presses.

UAE_Z28

iTrader: (14)

Thank you for the replies ya'll. I think I didn't describe the problem properly.

I have no remote. I just unlock the driver's door manually using the key, and when I open the door, I can hear the passenger's door being unlocked as if someone pressed on the in car door unlock button.

My car is a Japanese export, and I have noticed that there is a small box behind the headlights that is also missing from my buddy's Z28.

Also sometimes when I replace the battery and in the process of connecting the terminals a loud car alarm goes for a second, not the usual car horn alarm but a separate aftermarket alarm (viper alarm maybe)?

Okay edit: I found out that the small box is an alarm speaker that has the word HORNET on it. Any ideas ?

UAE_Z28

iTrader: (14)

Here's my door label if needed:

WhiteBird00

iTrader: (4)

Hornet is another brand name of Directed Electronics - the makers of Viper. I suspect the aftermarket alarm is the source of your oddly behaving locks.

1999nbmZ

Yup, suspect #1. Every time. If you don't have the remotes for it, work on removing it first. If you're using it currently, I would suggest finding a car stereo/alarm shop that deals with Directed Electronics, and have them diagnose, and clean up as needed.

Existing aftermarket electronics are my first thing to remove when I purchase a used vehicle. Get it back to stock, and working perfectly. Then I start adding my upgrades as needed.

Any other questions about it, just post 'em up!

UAE_Z28

iTrader: (14)

Alright thanks again, any idea where the previous owner would mount the alarm controller?

1999nbmZ

Normally somewhere around the steering column. Some installers will hide the module somewhere else, but a good amount of the wiring is done at the column. Drop that plastic trim and panel below the steering wheel, and I bet you'll find what you're looking for.