I recently purchased a 1984 Corvette with an after market Clifford alarm that appears to be from the late 90's to early 2000's. It has a remote starter key fob and is supposed to be able to remotely lock/unlock the doors, but I assume because of the remote door locks the doors won't lock anymore with either the key fob or the power lock switches inside the car and unfortunately it didn't come with the actual keys for the doors only the ignition keys. The first week we had it, it started up just fine but it couldn't be driven due to rotted tires but still started up perfectly and didn't sound like there were any problems. Then the car sat for about a month while we were on vacation and when we got back to work on the car again we replaced the battery as it was old, but as we were installing the new battery, the alarm system started going off as we tightened the negative terminal. The only way we could find to stop it was by holding down the large button on the key fob which seemed as if installing the new battery had just reset the alarm system or something, no big deal. But after we had installed the new battery we took it out for a test drive for about five minutes until you could hear beeping for a few seconds until the car turned itself off and the alarm proceeded to sound but this time the button on the key fob didn't work at all and the car seemed to have just locked itself entirely. All the lights inside were working but when I tried to actually start the car it just acted as if the battery was dead for one or two tries at starting until the alarm started to sound again. We had to remove the battery and push it back into the garage as nothing seems to be able to get it to start or shut off the alarm short of unplugging the battery, which we can't install anymore due to us not having a way to turn off the alarm while we're trying to install it