96 SL2-possible wiring harness prob?

My daughter has a 96 SL2, and generally the car runs fine. However, last night she reported that on her way home from work, as she was slowing down for a red light, her Check Engine Soon light came on, and the car stalled. She tried the ignition right away and the car turned over. The heater would not work, though. My husband drove it today, and said the car was driving initially, though things weren't working like they should have, like the radio and heater blower. The car finally stalled, and after a couple of attempts, it started up, and that time everything worked, including the heater, lights, you name it. She's afraid to drive it right now as she doesn't know what's going to happen.

She had a friend "fix" the car a few months ago. Her engine was squealing so he replaced the serpentine belt (I objected as he seemed kind of like a moron to me but he did it for free so my daughter accepted his help), though it continued to squeal for weeks afterwards. Is it possible that somehow the wiring harness has come loose, or there may be a short in the wiring someplace? My husband said it is an electrical issue, obviously, and if it's just a minor problem we can get it fixed for her. Right now things are so super-tight for her financially, so any advice that can be provided would be most appreciated. Thanks!

My daughter has a 96 SL2, and generally the car runs fine. However, last night she reported that on her way home from work, as she was slowing down for a red light, her Check Engine Soon light came on, and the car stalled.!

It is normal for the SES light to come on following an engine stall. The fact that the engine stalled while she was hitting the brakes hints that a power failure of some sort is a good possibility because the brake lights do take a good amount of power to illuminate.

Take the car to AutoZone or Advance Auto to have the alternator tested for free.

Remove and check the battery terminals and make sure they are clean and tight. Also check the three main ground connections and make sure they are all good and clean. One is near the battery, another is below the air intake, near where the engine & transmission mate together, and the last one is the ground strap on the passenger's side between the engine mount and the front right strut tower. Your car may not have the ground strap, so don't panic if it doesn't.

Check the positive connection located at the back side of the underhood fuse block on the driver's side. Make sure that connection is clean and free from corrosion.

I see you are also in Iowa (the heart of the salt belt) so corrosion at some of main power & ground connections is a good possibility.

Another possibility could be a bad ignition switch. They usually fail quite suddenly and cause some odd symptoms when they do. Unfortunately, there isn't an easy way to tell if they are bad before they short out and cause a bit of electrical smoke like they usually do. Again, this is just a possibility that I'm putting on the table. I strongly believe you have a bad power and/or ground connection somewhere so I would pursue that first.

Good Luck

Adding to what Ruley said, REALLY check those battery connections. Side terminal battery connections can be loose even though the bolt is tight.

And, the belt probably needed the tensioner replaced.

Thank you for the suggestions, my hubby is going to poke around in there today. He also believes there is some kind of loose connection that is causing it, since it has only happened periodically. I'll post what he finds. Have a wonderful New Year!

When the battery in my 94 failed (Autozone, Valucraft) it caused all sorts of bizarre electrical problems like you're describing. The Saturn wiring harnesses are pretty reliable, so like the previous posters, I'd focus on the battery and alternator.