hey sam I have actually installed 5 remote start systems and I can assure you they are very easy to install (the last one I installed took me 30 minutes). I see you have an 85 firebird so there will be no anti-theft you have to bypass.
HCR13 said he will find you the schematic for you, if he can not, you can find them on bulldog.com, 12volt.com and through autozone.com if you can't find them let me know and I can find them for you.
As far as location
-12V switch ignition wire (+)
-starter wire (+)
-12V accessory wire (+)
these are all located in the ignition harness. If you pop the cover off under your feet or closest to the pedals (I believe they call it the knee bolster) panel. These will be the thicker wires inside of there. The closest car to a 3rd gen (I would assume) that I installed one in was a 90 olds cutlass (was about 10 years ago when I installed this so please double check) I'm not sure what color the switched ignition is, but the proper way to test this wire is
1: probe the wire with a test light
-key off there should be no power or no light with the test light
-key on there should be power or the light should come on with the test light
-turn the key far enough so everything shuts off in the car but before the starter cranks this wire should still have power when nothing else does
for the starter wire I believe it is yellow but to double check do this
-key off no power
-key on no power
-starter cranking is the only time you will have power to this wire
For the parking light wire. Take your headlight switch off and probe all the wires with the switch set to off make notes of which ones have power and which do not then turn your parking lights on and find out which wire has power that didn't have power when the switch was off. This one is easy to find and if you find the schematics you know the wire to test right away.
For the brake light under your knee bolster panel, somewhere along the brake pedal there should be a switch with 3 wires? coming out of it check all the wires and the one that has power when you press the brake pedal is your brake wire.
For the tach input there is a couple of options here
1. your remote starter "should" have 2 different settings to let the unit know the car is running; tach or voltage.
2. to find your tach wire (assuming you have an analog dash digital is different trust me I know from experience) I believe it is the white wire that goes to your instrument cluster (again double check). THIS IS VERY IMPORTANT to test this you need to use a voltmeter instead of a test-light as a test-light could damage something (I'm not sure why or how but that's what was explained to me) anyway with a voltmeter it will read somewhere around 5 volts ONLY WHEN THE ENGINE IS RUNNING. This will be your tach wire.
3. I would recommend setting your remote start to voltage sense the way this works is, you have a 12 volt battery and your alternator puts out 14.4 volts so once the remote start unit senses more than 12 volts it will stop cranking the starter. The last 4 starters I put in I used this option and had no problems whatsoever but if your alternator failed I could see potential problems. Also I have heard this doesn't work as good with older cars so I'm not sure but I would definitely try it.
For the door pin switches, first off I will tell you that I never did get these to work and I have no idea why hopefully someone will chime in with a reason why as this has always bugged me but all you should have to is locate the door pin switch which will be located somewhere in the door jamb to know you found it open your door and push on the switch if your domelight shuts off that is your switch. As I understand there is a negative polarity running into one wire of the switch and when the switch closes the other wire also has negative polarity so basically push the switch in and out and whichever wire gets the negative input is the wire you need again this did not work for me and I have no idea why so hopefully someone has some more input.
Also another way to test MOST of these wires which probably isn't recommended is to jump any of these wires directly from the battery to the wire your trying to test but make sure you have the polarity correct ( + to + or - to -).
Also as
HCR13 said you can use quick connects but I would not recommend them (if we are talking about the same thing) especially on any of the ignition wires since these actually cut some strands of the wire I have used them without any problem in the past but I still don't like them. I decided long ago I would not put a remote starter in another car I owned since you really hack into a lot of wiring. But part of that problem has been fixed since nowadays bulldog makes an "Ignition T-Harness" which basically you just wire everything into your t-harness and when you install the starter it is basically all plug and play. Unfortunately I was gonna order one for my 2001 grand prix the other day and noticed that it has been discontinued but I think you could easily make one if you could get the harness from a junkyard and basically splice them together.
Now I know you said you are not really an electrical guy. But when I installed my first remote starter I did not even know what the hell "ground" was, but now I am really confident in auto wiring and have added many auto accessories because of what I learned by doing this. If you have any questions about what I said in my post (I know it got wordy) pm me and I will walk you through this. I can give you my phone number also if you would like. Let me know any questions you have with this.
