Flikering lights

Sounds like a bad voltage regulator.

Thanks.

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----------------------------------------------------- Matthew Fries Minneapolis, MN USA snipped-for-privacy@baloneyvisi.com

"Quit eating all my *STUFF*!" - The Tick

Wow, that sounds sadly simple. Other people suggest that it could be anything...

Saturn utilizes a built in voltage regulator located inside the alternator. Since the OP said that the problem predates the recently changed (new? rebuilt? used? tested???) alternator, I suspect that the problem is elsewhere. The OP unfortunately did not say how long he has had the car or when the flickering light problem began or of the frequency of the flickering. He also does not say the age or condition of the battery, many electrical problems and failed starters and alternators are due to poor batteries. What killed the original alternator? Since cleaning the battery connections and ground seemed to help, this is an indication of the place to start troubleshooting . Perhaps it is a bad cable or wire other connection. I suspect that this problem will require a LOT of time to chase down.

My thoughts exactly. I doubt he has a load test tool so the cheaper thing to diagnose this is to swap that cars battery with another cars battery. If its more than 5 years old a new battery is likely needed...

The whine you hear in the CD player might just be alternator noise and can be remedied with a hash filter on the power line. Could also be from the spark coils but that's unlikely. One thing that since you changed the alternator, I should mention what happened to me similarly. I had changed the alternator on my chrysler minivan after the second Nipondenso alternator (original equipment) burned up. I replaced it with a Bosch unit which had higher output. Unfortunately, while it performed its task beyond expectations, it created noise on the radio that could be heard even with the volume way down. Traced this back to the type of diodes used in the alternator (avalance rectifiers) that are lower loss but switch very fast and tend to put spikes on the electrical system. I added a filter to the alternator output which cut the noise significantly.

Yes, I read that you checked the ground connections. There are a slew of them too and they can drive a tech nuts trying to find a bad one. It is often better just to add redundant cables, for test, at least. A little corrosion on a ground wire or body stud can make for an unreliable connection. Big one to check is the battery to engine and engine to frame electrical connections. Other than that, have someone watch the lights while you start tapping about with a rubber mallet and wiggling harnesses. There may also be some problem with the through the firewall electrical bundle or fuse panel. See if the affected circuits trace back to a single fuse or to a common ground lug.

Hope you retain your sanity while hunting

My experience (which is Canadian climate related) is that almost any car will give safe and acceptable service IF you make sure you ALWAYS have enough clean oil and coolant AND a GOOD battery and in the winter only use tires (all season radials OK) with GOOD tread. (In the summer the tread is not as important so I like to keep a spare set of rims so I can use worn tires in the summer and new tires in the winter.) Brakes are always important.

Lots of electrical problems can be caused by waiting for a battery to fail before replacing. Most good batteries will last 5 years but any more is borrowed time, better to save old batteries for spares or summer use in non esential vehicles. Batteries are cheap compared to starters and alternators and are much easier to change. A cheap new battery is usually better than an expensive old one, and price is seldom an indicator of quality.

just my .02

Sorry, I've had my car 1 year. What killed the original alternator was driving with all of the accesories on (wipers, lights, air, radio, and then breaking to shut off cruise control)

As for the battery, its about a year old as well, since when I got my car, I kept forgetting the lights on (the bell only sounds when you start the car, no other time! Another problem I'm investigating now that I have free time))

I dont have a load test tool...how much are they, etc?

I dislike the type of battery I have now as it is not the "maintence free" type. I recently checked the water levels and they were fine. I'm thinking about changing it (already in my next paychecks spending) along with plugs, since I was foolish to ever try Bosh platinums...

This does not sound like something that should kill an alternator. Do you live in a very hot climate?

Most good auto parts stores will have a load test tool and will test your battery for free.

Get the battery tested first if it is only one year old, it should still be good and if it is faulty you may have a warranty although battery warranties are often not much of a benifit. Like the alternators, batteries do not seem to like really hot (or cold) climates.

I agree with Oppies post and also wish you good luck retaining your sanity while looking for the bad wiring connections.

I have the same problem I started the car then disconnected the positive cable to the battery so car was justed using alternator turned on lights still flickered tried stop lights stilled flckered and dimmed for a moment. should a good alternater not do that when not connected to battery. or is that normal when just running on alternater

peter

Good question. Someone here sugested that I swap a battery with another car. unfortunately I only own 1 car, and this is it.

I'd gladly buy another (or two!) SC2's - they are fun to drive! My friend rode in my stock SC2 and liked it enough to buy a performance modded one.

I should also note that this is my first car, I live in an apartment, and the only tools I have are at my parents 30 minutes away.

Disconnecting the battery while engine running on a modern car is a big no-no (as is pulling off spark plug boot to check spark on the fly).

The battery serves to ballast the charging system and evens out the pulsation of the charging system. Without the battery in circuit, you can get some pretty large voltage excursions and transients that can potentially damage ALL the electronic devices in the car. The electrical system in an automobile is actually pretty hostile, approaching military requirements on design practices and component reliability. Many of the newer modules are better designed and can take more abuse but do you want to take a chance?

Similarly with pulling off a spark plug wire while the engine is running, the voltage no longer arcs to ground and the output of the spark coil is no longer 'clamped'. This causes the spark coil primary voltage to rise very high and stress the transistor that drives it.

So, to paraprase 'Dirty Harry', "Do you feel lucky?" if so, keep doing the same 'ol.

Oppie (electrical engineer)