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Car Alarm Installation...

G

Guitarist575

New member
Ok, I bought this car alarm... After skimming through the manual, I see one thing I don't quite understand.

There are wires for Lock COM, Lock NC, and Lock NO.
What's up with that? Lol

If it matters, I'm in a '97 GT.
 


Lock COM - probably the ground wire, or could be the common connection on the relay
Lock NC - Lock, Normally Closed, probably a connection to the relay for the alarm
Lock NO - Lock, Normally Opened, same as above, just open

Normally opened and normally closed refers to the relays state with no power applied to it.

relaytextA.gif


The common is connected to the NC in its power off state. So whatever is connected to common flows to the NC terminal. When power is applied the relay connects to he NO terminal and what is connected to the common will then flow to and be connected to the NO terminal.

Hope that helps out.
 
thanks, that cleared up a lot. one more though...

'Purple wire: TACH wire(AC input) connect to TACH signal wire (coil or injector)'

Am I correct in assuming this means tachometer? where might I find this wire?
 
That one you are going to have to wait for someone else on as I am not sure. I believe, and dont quote me on this, but I believe that wire would probably come from the crankshaft position sensor, if not there then it would come from the PCM.
 
it's the tach wire, and can be found at the coils, check out 12volt.com for a diagram on where everything is located
 
I will try to get you some directech sheets on the wires, where they are and what they are by later tonight or tommorow.
 


Ok, I put this project on hold for a while due to lack of free time...
Everything works except remote start. Well remote start probably works, but i haven't tried it because I don't want to fry my starter or anything because the system has no way of telling when the car's started.

I looked at the12volt.com, and they have two pages on the '97 GP.
This one: 1997 Pontiac Grand Prix Alarm, Remote Starter, Keyless Entry Wiring Information
And this one: 1997 Pontiac Grand Prix Alarm, Remote Starter, Keyless Entry Wiring Information

The first one says that the tach is the purple/white wire from the ignition module, but does not say that it is an AC current (the alarm system requires the tach signal to be AC).
The second one says it's the white wire on the driver's side of the PCM and that it's AC.

I'd like to use the one from the ignition module, as touching the PCM scares me :)
My question is, how would I test AC current in the car with a multimeter? Where would I put the ground side? Can I ground an AC current into the car's DC ground?

Also, where would I find the ignition module? Do the wires that run from the ignition switch go straight into the ignition module? I'm pretty new to this.
If I can't use the ignition module wire, I have another dilemma :) I moved my PCM around while getting rid of my airbox to install my cold air intake. I don't really remember which side of the PCM was on the driver's side before.
 
Last edited:
Sorry to bump such an old post...
I finished the alarm installation a day or two after my last post on this and thought it might be good to post the solution here for anyone else with the same problem.

The correct wire is the white one towards the right of the harness on the ignition control module. I'm pretty sure it is the 5th one from the right.
I got a hold of GM's techline software and looked it up in there before trying. I didn't even have to touch the PCM.

Also on my alarm (not sure if they are all like this) it won't start unless the parking brake is applied. I just tricked mine into thinking the parking brake is always on.
 
Guitarist575 said:
Sorry to bump such an old post...
I finished the alarm installation a day or two after my last post on this and thought it might be good to post the solution here for anyone else with the same problem.

The correct wire is the white one towards the right of the harness on the ignition control module. I'm pretty sure it is the 5th one from the right.
I got a hold of GM's techline software and looked it up in there before trying. I didn't even have to touch the PCM.

Also on my alarm (not sure if they are all like this) it won't start unless the parking brake is applied. I just tricked mine into thinking the parking brake is always on.
Click to expand...
you have one designed for a manual is all
 


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