Speakers shortage

[bird]

I've got a 99 Disco II with the Harmon Kardon stereo package. the truck is getting up there and of course some things will go.
i replaced the front door tweeters a few weeks back, and when i was testing the others i realized that the rear door tweeters were out.
picked up two "new" ones, and got to work. upon pugging in the first, i got nothing. figured it was shot as well and put in the other one.
it worked. wonderful... but in the time it took to go to the front and turn the radio up a little to make sure, the speaker was out.
I am trying to find out if there is a fuse, or a possible cause for a short in them.
if one speaker is out, will it then short out the other?
i am getting two NEW replacements to switch out, but before i pull the panels off again, wanted to see if there were any precautions i should take before testing them installed.

 

[alzerom]

Tweeters are the most sensitive part of a bi-level system. They can be killed with simple over voltage, over driven... etc. Get some tweeters that are rated at double the power of the existing tweeters. Then when you install them, with everything OFF, touch to two power wires together quickly. If no spark, proceed with the installation. If spark, then bleed the power out of the amp and briefly touch the wires again. You will be surprised at how little juice it takes to **** a tweeter, and static during installation is more than enough.

There is no fuse. The amp could be putting out too much high frequency stuff which can cook tweeters (turn the treble down). Over voltage can cook tweeters. The fact that so many of them have gone out indicates the actual problem is in the radio/amplifier.

I would ask myself if it's worth the hassel.