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Computer? Alternator? Something else?

Hello all,
I just had my '97 Pontiac Sunfire in for an inspection, and to get it road-worthy for a trip from PA to FL and back. Since I got it back, it has had a laundry list of minor issues, and I am wondering what might be causing them.
First, pretty much every console light is coming on/flashing at random times, including the emergency brake light when the brake is not engaged, and the seatbelt light when the seatbelt is securely fastened.
Second, the daytime-running lights/headlights work until the first minor bump, at which point the console light for them begins flashing, and the headlights stop working altogether.
Third, the needles on the temperature and RPM gauges will bottom out, along with the oil, battery, and coolant lights coming on. The car still runs, and the gauges soon return to normal, but it does this repeatedly.
Any thoughts as to the cause? Could it be the computer resetting itself after the battery was disconnected? If so, how long can I expect it to take before the computer fully resets itself, and things get back to normal? If not the computer, what else could it be? I had the battery tested with the car running, and it doesn’t seem to be the alternator, although it’s possible that a bearing could be going in it, based on a noise my wife claims to have heard coming from the alternator.
Any thoughts or suggestions? All are welcome.
Thanks.

Rent a car if you can splurge. Much more comfortable likely better MPG and no worries.

Sounds like an intermittent bad electrical connection.

Well, we really can’t splurge on a rental car right now, but thanks for the suggestion. Also, spending the money on having my car repaired is more beneficial in the long run, IMHO.

Thanks, jesmed. Do you think it would just pop up all of a sudden like that? I mean, before the car was in the shop, it ran fine and wasn’t giving me these problems, only since I got it back.

Try removing both battery cables from the battery. On the positive cable peel back the red rubber cover to expose the battery terminals. If a lot of corrosion is found on the terminals replace the positive battery cable assembly.

Tester

Let me suggest that you find a mechanic who is knowledgeable in automotive electrical systems. An understanding of electrical current and a wiring diagram might make for a fairly quick resolution to the problem.

And, the problem may very well be the result of an inadvertent mistake by the shop doing the inspection. But then, on the other hand…

Maybe there’s a problem with corrosion or scale on the junction terminal which is located near the battery positive post. All electrical power for the car goes through that terminal except for the starter motor windings and it only takes a few minutes to disassemble and clean.

Thanks, Rod Knox. I am taking the car back to my mechanic on Thursday, and I wanted to get an idea if there was anything else I should ask him about, since he’s always been honest and straightforward with me.

Thanks, ok4450. I’ll ask my mechanic to check that.

When a lot of the console guages and lights act up, my first suspicion would be a faulty or oxidized connector. Look for a connector which connects to the console, pull it and see if the contacts are oxidized. If so, clean them up with a pencil erasor. However, a console connector problem wouldn’t usually cause the headlights to turn off. That’s the weird symptom in this report. Usually the only thing that would cause the headlights to turn off would be a faulty headlight switch or a faulty headlight relay.

Many cars have a large ground connection between the engine block and the chassis. Check to see if yours is damaged.