Click and Clack diagnosed the same problem on a show about 10 years ago. As I remember, the car was a VW Rabbit. The diagnosis was a defective starter relay. They also reported having a car in the shop where the starter motor started cranking the engine while the car was on the lift but unattended. As I remember, the starter motor actually caught fire.
My only other thought is that maybe your Saturn wants to run away from home. I have had some cars that I wish had decided to run away. I would have made it easy for them.
Those are good points VDCdriver. And you are right, to the best of my knowledge there is no remote start system. I will look into that more. Triedaq has an impressive memory recalling a show from 10 years ago. It’s more evidence to support the starter relay theory. I have the negative terminal disconnected to avoid any potential fire risks. This saturn has been a great car. Amazing gas mileage, low maintenance costs, but not much fun to drive… maybe I should just open the garage door and set it free.
I plan on taking care of the problem this week, and will let you all know what I find out. Thanks again for all the great input!
Well the mystery has been solved. There are two terminals going to the starter. One always has power going to it, the other (s-terminal) is supposed to get power when you turn the key, engaging the starter motor. The wire on the s-terminal had been rubbing against something which removed a small portion of the wire insulation. The wire was also too close to the power terminal, causing a short, or arc to the s-terminal and periodically engaging the starter motor. It was a simple fix of moving the wire going to the s-terminal. Since the short was on the other side of the ignition and clutch switch, those safety’s weren’t preventing the problem. No doubt, I’m very fortunate the starter was never shorted out for very long. There could have been a lot more damage or even a fire.
Thanks again everyone, and happy holidays!
I parked my car near a old Maruti Suzuki Omni car at a place nere Alua, ernakulam, India. It was in a dark place, in night about 8 00 PM. the Suzuki Omni on its own started and was moving ahead as if it were accelerated and simultaneously breaks are applied. It was jumping, jerking and moving ahead. I thought somebody was riding it from within. Then a few men rushed to it and opened its door and applied hand break and asked me to escape, because the car is behaving strangely. It is a old, non-automatic car. Could it be a mechanical fault?
If the starter motor turns on & starts spinning and the car is in gear the car will definitely attempt to move. Whether it does or not depends on how strong the emergency brake is set. The starter motor is like any other electrical device, it can fail. And can fail in a way that it turns on all by itself, for no apparent reason. There been a few callers on the Car Talk radio program who’ve had this mystery. Replacing the starter motor is usually the solution. Inside the starter motor there’s some high current electrical contacts which can sometimes sort of weld themselves together apparently.
I had this happen inside a steel plant with a gasoline engine tractor trailer many years ago, before we had Maxi Brakes. The bearing in the end cap of the starter on a 534 cubic inch Ford V8 wore out and the winding’s of the starter shorted out against the case. I had shut the rig down and was standing next to the receiving clerk when it happened and it hit the flatbed in front of it.
It would have stopped soon anyway because it melted some of the battery cables.
It had 4 big 6 volt batteries wired in series/parallel.