Grand Prix tries start while running and driving

My 2000 Pontiac Grand PRIX tries start by itself. It will start trying to turn over even though im driving down the street. Then when i stop and turn the key to the OFF position it will try to start again and i have to turn the key and turn it on. The only way to turn it off is to disconnect the battery.

just had the wiring harness replaced and starter replaced. FYI...:runaround:

thanks PLEASE HELP>>>>>>>>>>>>>>>>>>>>>>>>:crying:

PM me an email address & I'll send you a wiring diagram for the starting circuit. It's probably the ignition switch but could also be a relay.
Remote starter installed?

my email account is smsmith1988 thanks..

no remote starter so idk what could be the problem

just had the wiring harness replaced and starter replaced. FYI...:runaround:

Which wiring harness?

ignition switch

That looks like just a partial email address but I just looked at the wiring diagram & neither the 3.1 or 3.8 use a starter enable relay. The power comes from the ignition switch through the park/neutral safety switch to the starter. So even if the ignition switch is faulty & sending power to the starter while in run the power shouldn't pass through the park/neutral switch while in drive or any other gear. Was the wiring harness replaced to fix this problem or did the problem start after the harness was replaced?

both the starter and the ignition switch were changed due to this problem about 2 months ago and now its happening again. also i bought the starter refurbished does that make a difference.? my email address is [email protected] sorry about that. I really appreciate all your help im a college student and need to get to class. thank u

I would look at the wiring near the starter. It sounds as if you have a wire worn or burnt through arching, causing the starter to engage when not desired. Something to check (if you can get it to do this while in the driveway), hook up a test light to the "s" terminal on the starter solenoid (it's the small post with the purple wire attached) and see if it illuminates when the starter engages on its own. If it does, then you have a bad wire somewhere. If it was doing the same exact thing before the ignition switch and starter were replaced, then it may (notice I said may) be safe to rule those out for now. I think your problem is in the wiring somewhere. All those wires to the starter run close to the front exhaust manifold, so heat damage to the wiring is very possible.

Wiring diagram has been sent. As a temporary fix you could install a push button switch inside the car. Remove the small purple wire from the starter & connect the switch wires between the purple wire & S terminal. To start the engine you'll have to press the push button & turn the key to start at the same time.

If the temporary fix cures the problem then you need to figure out if the ignition or park/neutral switch is bad.

well today and yesterday it has stopped doing it but it makes me a little nervous to drive it..i looked at the old wiring harness for the ignition switch today and there was a cord soming from there that was red like (speaker wire) and had a fuse attached to it with a piece of black tape over it.....old automatic starter? and if this was taken out is there a possability that there is still some type of cord or assembly still in the car? Where could i look if this is possible?

most aftermarket remote starters are mounted under the dash near the steering column for close proximity to the wires that need to be spliced into. these days they are about the size of a paperback book or dvd case (just a little thicker).

most aftermarket remote starters are mounted under the dash near the steering column for close proximity to the wires that need to be spliced into. these days they are about the size of a paperback book or dvd case (just a little thicker).