I am hoping for some insight....

I own a 96 Volvo 960 (daughters car) that recently began having starter issues. I purchased a Bosch starter & had it installed while out of town. The garage installed the starter last Wednesday & we picked it up yesterday (Monday). They claim they started it daily because they kept it inside their garage & had to move it out each day & back in each night. My son drove the car home & parked it in the driveway. Approximately 1 hour later we heard the car attempting to start on its own with no one in the vehicle. I jumped in the car & saw that the key was not in the ignition & was turned to the off position. I got out of the car & while attempting to disconnect the negative terminal the battery died stopping the "starting" process. I put a trickle charger on the battery & charged last night to a reading of 12.6 volts. I attempted to connect the negative terminal & the car once again tried to start without a key. I disconnected the battery again & decided to stick the key in the ignition & turned it to the 2nd position. I then connected the battery terminal & the car turned over & started & also the hazards came on (without the button being pushed) & the ABS light stayed on. I turned the key off & the car stopped running but the starter continued to turn as if attempting to start again. I disconnected the battery (negative) & looked at the wiring on the starter although had a tough time seeing (even with a flashlight) because by this time it was dark outside. I couldn't quite make out the wiring but it looked as though the positive terminal & the wire to the alternator were on the larger top post which I believe is correct. There is a smaller wire (green) that seems to be connected to the same post but could be connected to a lower post but can't quite contort my body to see if it is connected there for sure or not. Could this smaller wire, which I am assuming is the ignition switch wire & if I do find it to be connected to the same post, cause this to happen? I plan on going home shortly to jack up the car & get a better view from below.

Sorry for the long post but wanted to provide as much info as possible to start.

Thank you for any help anyone can provide.

 

If the car tries to start on it's own, there is an electrical problem for sure. The video below show how the starter is connected on the 850 which should be the same on the 960, they are both white blocks.

The thing about it is, the main power lead should NOT be getting any juice unless the key is on. The starter solenoid should NOT be charging the starter to turn unless the key is in the III (start position). My guess is that the ignition switch is bad and needs to be replaced. Not sure how it would "all the sudden" break like that but it's the only thing I can think of.

I thought I put together instructions for replacing the ignition switch on the 960 but I can't find them. Basically you:
1. Remove the tilt **** with an Allen wrench.
2. Remove the collar around the steering wheel.
3. Unplug the ignition switch.
4. Remove the 2 screws that hold it to the steering column.
5. Plug the new one in and install.


Volvo 850 Ignition Switch Replacement

 

RSPI,
Thank you for your response.
It was definitely an electrical problem. I put the car up on jacks & noticed the mechanic had tightened the positive cable & wire to the alternator to the post so that it was against the wire clip from the ignition switch. I loosened the nut, pryed the cables away with a long screw driver, retightened the nut & coated the ignition swith wire with paint on electrical tape. I had to do this because the old plastic clip cover had corroded & broke off so there wasn't any protection from arcing.
This did the trick so won't be changing the ignition switch (this time) but thank you for the info & your input. It is much appreciated!

 

Wow! I really hate paying people to do a hack job. So sad.

Why would he mess with the alternator connection?

 

I typically do a lot of my own work however we were leaving town, my daughter didn't go & it was her car, so she was able to use my car while I was gone & it needed to be taken care of.

The cable to the alternator that connects to the post (on the solenoid) along with the positive cable from the battery is right next to the igntion switch connection on the solenoid. The plastic connector that typically covers the clip from the ignition switch was broken off & had slid down the wire. This is actually what I noticed first when I looked under the car. They (Mom & Pop place) have typically helped me out with issues in the past on things I just didn't feel like dealing with but they should have noticed the wires touching.

 

It likely wasn't very tight and moved. I didn't realize that the connection has power all the time.