Here is one for you.

I bought a 3000GT 95, came with a factory alarm. Previous owner had a LoJack installed into it as well but did not disable the factory car alarm. My alternator died a few weeks ago and I had it replaced.

Now the car has problems starting which I have linked to the alarm. There is just no power to the ignition. I have tried to disable the LoJack but cannot get the car to start by unplugging the LoJack. Using a multimeter, the Lojack is providing power on its ignition line that goes to the ignition relay.

If I fiddle with it, sometimes hours, I can get the car to start. It seems that there is something with the passenger side door. That is the best I can narrow it down to, opening it and closing it sometimes allows the car to start. Time also seems to be a factor, if the car sits for hours it seems to start with a higher success rate. If I mess something up like unlocking and relocking the doors without starting the car or forgetting to lock the doors (lojack automatically locks them), the car has a hard time starting.

I have have a few ideas of stuff to check, door switch (but the alarm doesn't ever go off unexpectedly and won't go off when i open the other door), valet switch on the LoJack (but even when set to valet the car won't start, but sometimes in valet mode the LoJack activates when it shouldn't) or ignition relay (not sure if this failing would cause something like this to happen).

Is there a way to disable the factory alarm for the 3000GT and have the car start?

Does anyone know if I pull the main connector out of the lojack (no power to the lojack), should the car start?

Could this be an ignition problem and the door switch / alarms have nothing to do with it?

 

I had the same problem with mine not starting. Like you said It will and sometimes it won't. I had local so called mechanic to look at mine. He said it was my ignition, bought one and that wasn't it, tried to put a new ignition relay in it, and it still would not work. It has a factory Viper alarm, and I just got him to take it out/unhook it, and it starts up great now. It is in that alarm you have I beleive don't quote me on this. I say this though, mine alarm worked half a** anyway. I only heard it go off twice since I had the car and it's been 3 years now. It would only go off when used the key to get in the door, when the door was locked GO FIGURE!

 

i pulled the fuse for the alarm and the door locks on my eclipse, not sure if they are similar systems or not, but the alarm would still activate when i locked the doors, even without the fuse, so i pulled the door lock fuse and now no alarm problems, if your not worried about having the alarm, i would try that, u gotta lock the doors by hand now, but its better than the alarm screwing with your ignition.......

 

Hi, I joined this forum after searching web for this exact problem and finding results here. Sometimes no power to the ignition system, and I would fiddle with the key, back and forth a lot, and eventually it would start. I noticed it was worse in cold, and got worse as it got colder. That turned out to be coincidence.

Many theories... but in short it turned out to be the most obvious problem: The ignition cylinder/switch.

I took the column apart and found that the little recieving wire cluster on the left side had some very minute play (like <1degree). If I hold that in my left hand and turn it back towards my, while turning the key with my right hand, it starts without fail. If I don't hold it, it's back to 100x trying first. But at least now I can see it so I know what it is.

Well, that was my problem and solution: simple mechanical wear which worsened itself exponentially due to rambo key turning.

Mine was prolly just a fluke, but if it helps someone out there, then great!

 

Just joined,I have a '95 GT base model.Had start-up problem last year,would get a "dead click" occasionally 4 mechanics gave input ranging from Starter-battery-alternator....
All were wrong!

Problem solved with new starter relay.

This is late input for original post but maybe will be helpful to others=).

 

I have a 1991 3000gt and I have had issues with the starting system as well. The first time the car wouldn't start I had to replace the ignition, however, the starting system starting acting up again..so I took my car in and the mechanic said that my alarm was interfering with the starting system, and he said the only way to fix that problem was to take out the alarm, so he did....and now the car starts fine.