Alarm question

I have a 99 chevy blazer. Is there any way to find out if I have a factory installed alarm. If I don't do I have to get a bypass module to install a remote starter alarm. If there is a factory alarm where can I get the transmitters. Any help would be appreciated.

since about '94 the S10 blazer came with factory "keyless remote" option, so even if an aftermarket was installed (if installed professionally), it would be 'junctioned' into the original wiring harness, allowing the factory system to still operate.
the best place to acquire a GM remote is GM. you can go to a parts house in Indiana, but most AutoZone's, Checker/Schucks/Kragen's, etc. will only order a GM one, and merely mark it up; or worse, get you a "universal" remote that doesn't work on anything, and hope you can program to your vehicle; because if not, it's a paperweight.
go to Chevy/GMC dealer and order one, it will be under $100. and can be easily programmed to your vehicle...
plus, your profile says you have an industrial job (warehouse mgr?); make a copy of your company's tax license, when you place your order at the dealership for the remote, tell them if is for a company car for your business: your cost will be 10-30% less than retail AND tax free.

hope this helps,
ctesla