Got an issue with my 02 TJ Magna (3.5 V6). I pulled up at a bottle-o about 2 weeks ago and turned the car off - when I went to start it again, as soon as I put the accessories on, the car started itself and the starter kept going while the car was on. Turned the ignition off and the engine cut out, but the starter motor kept cranking the engine over.

With the keys out of the ignition, and the engine still cranking over, I popped the bonnet and disconnected the battery to make it stop before something burnt out. Reconnected the battery and the car was fine. Starter motor acted normal - started the car fine, didn't keep running.

Thought it was weird, but assumed I may have got a bit of water on the contacts or something as it was raining pretty hard that night and went through a few puddles.

Wife called me yesterday as the Magna was cranking over by itself when she went to move it on the driveway. Told her to disconnect the battery and reconnect it - which solved the issue again. Thought i'd look into it - thinking possibly a sticky contact in the starter relay.

Before I've had a chance - wife took Magna to the shops today. Returned to have the starter motor not working at all. Seems the solinoid isn't firing. Can hear the starter whir, but no cranking.

Obviously i'm going to have to change the starter motor, but was wondering if anyone else has had the issue of the Magna cranking itself even when key is out of the ignition - and if it is the starter relay - or if it is something else? I also wonder if the starter has stuffed itself while the wife was in the shops because it kept itself cranking?

ive had a simular problem with a TF magna i owned, it was the starter motor itself that was playing up in my case.....but with mine, i would turn the key to fire up the car, and the starter would stay on, i would shut the ignition off and the starter motor would still keep running, crawl under the car and give the starter a wack with a hammer was my solution. best bet i can give you is get another starter from the wreckers just to make sure its the starter motor at fault before buying brand new

I once had a problem with a vintage car I owned. It was 6 volt which means the cranking current is twice that of 12 volt. The contacts inside the solenoid had become so rough and pitted they did not release. I fixed it by filing them smooth & shiny.

On another car I owned, the detent in the ignition switch had worn to the point it would often stay in the start position and I had to turn it off by hand.

Only ever come across this once, with a starter caked in years worth of oil and road dirt.
You will definitely need a new starter. If the old one is oil soaked, you will need to fix the leaks as well. If you get one from a self service wrecker, don't get one with oil all over it. lol

I think there should be a "starter motor relay" which could be faulty.

The Solonoid on the starter is the realy

The Solonoid on the starter is the realy

Is this the same on all cars or specific to the Magna?