This Ion belongs to a young man I know. He asked me what was wrong wit it. I’d suspect it has something to do with the door latches or door light switches. I know that’s a common issue on Tauruses, but I can count the number of times I’ve been in a Saturn on one hand. Neither if us is close the car for an easy look-see. Are the door light switches in the latch like a Taurus. If so, is the fix the same, spraying some electrical contact cleaner into the latch to clean the switch? If not what do you think it is?
Far from a silver bullet, but I have seen a number of Saturns that had unexplained warning lights/chimes, erratic interior lighting, erratic or no instrument cluster operation, door locks either inop or operating on their own, etc. All turned out to be faulty Body Control Modules.
If I recall the courtesy light switches are plunger switches on the jamb.
The BCM controls it all. I would check the battery condition and battery terminals and grounds before replacing it.
There’s a lot more to check and test other than battery terminals and grounds, and you won’t be able to check those things without a decent scan tool. You’ll also need a scan tool to replace the BCM. But we don’t know yet if the BCM is even the problem.
He’s not going to like that answer, but I’ll tell him tomorrow. It’s his last Sunday as a summer intern at my church.