So, my fiancé bought a blazer 2 years ago. (2000, 4wd) the tailgate (not the glass part, the door itself) stopped locking with the other 4 doors. When you do open the tailgate (only after doors have been locked) the alarm goes off? (AS FAR AS WE KNOW THE CAR HAS NO ALARM SYSTEM) it also goes off if you have the windows down and the doors are locked and you say reach through the window and push the unlock button. This is worrying him because he just put a subwoofer system into it.. and it already had a dvd/tv system in it when we bought it.

now the weirdest part to me.. we were talking last night and I told him to go out and manually lock the tailgate with the key.. don't know why this hadn't occurred to us yet. He comes back in and says he has no key spot on the tailgate!!!!!!!! the circle is there but someone removed the cylinder and just put a black plastic piece there instead, you cant press it in either.
(Seems to make sense that the alarm goes off when its opened and the doors are locked then)

im wondering if this is normal? Im thinking the previous owner had modified the security system? whenever the doors are opened the security light blinks but its never caused us any problems.


the main question is, HOW DO I GET THE TAILGATE TO LOCK???!!
the alarm going off when its opened is ok as long as were at home, but whats stopping someone from getting into the car when were not home.. cause we wont be able to hear it going off or anything.

my thinking is he should get a new keyless remote since it did lock when he had one. just thought id ask on here to see if anyone with more knowledge has any ideas.

 

Everything you describe seems completely normal to me. My 2000 came stock with an alarm system, as well as all the other 98+ style blazers I have ever been in. By locking the doors with just the lock switch (or key fob) you will be setting the alarm. The alarm sets about 30 seconds after the last door is shut (after pushing the lock button).

The tail gate on mine has no lock cylinder either, just the black plastic button that opens the upper glass part of the lift gate. As far as I know, that is the way they came stock from the factory. Yours might just be sticky/stuck. To lock the tail gate, just hit the lock switch in the truck. As far as I know, there is NO way to manually lock/unlock it.

Once you lock the doors (with the lock button/key fob), the only way to keep the alarm from going off when opening the door is by either unlocking with the key fob, or by unlocking the door with the master key. If by chance you get the alarm trigger, you can turn it off by either hitting the panic button on the key fob, or by starting the truck with the master key.

I would get a key fob, that would probably solve all of the issues you are having

 

^ Yup, what they said.