electrical surging at 2200rpm

[baldhead]

after running the taurus pretty hard last night I started having funny preoblems. The low beams would brighten along with all the dash and radio lights and the batt. light would come on all at 2200rpm or higher and then not happen at lower rpm. It also caused the headlights to cut out and the power steering too. All fusses are good and connections appear tight. thanks for your help,

[Willyum]

Just a guess, but a lot of electrical problems can be traced back to the electrical system trying to compensate for a failing battery. Might be worth having it checked.

[TomV]

Serpentine belt could be loose, tensioner getting old, alternator/voltage regulator intermittent, battery problem.

[shorod]

Originally Posted by baldhead

after running the taurus pretty hard last night I started having funny preoblems. The low beams would brighten along with all the dash and radio lights and the batt. light would come on all at 2200rpm or higher and then not happen at lower rpm. It also caused the headlights to cut out and the power steering too. All fusses are good and connections appear tight. thanks for your help,

I'm assuming this is on your 1996 Taurus? I'm also confused, you mention the low beams get bright, and later say that the headlights cut out. Did the headlights get bright one time, then later turn off? Did they come back on after going out, or did the high voltage maybe burn out the bulb? Maybe the surge in voltage caused a fuse to blow?

Now, why did the voltage surge, and did it surge outside of range, or you were used to a weak battery and once your engine speed got fast enough, your alternator was able to compensate for the weak battery and bring things up to normal operating voltage? Not likely since you mention the battery light came on. The charging system light should come on when a problem with the alternator is noticed, not just due to a weak battery.

I'd suggest you start by verifying all connections at the alternator are clean and tight. Also, inspect the connections at the battery to be sure they are clean and tight as well. Check where the cables terminate, at the fuse box for the positive cable, and at the block or chassis for the negative cable.

You may want to stop by a parts store or automotive battery store and have the capacity of the battery tested (load test).

If you can duplicate the problem and have a voltmeter, rig up a way to monitor the battery voltage while driving and see what the voltage is doing when it acts up. If the voltage is getting higher than 14.5 volts for more than a fraction of a second, you have an alternator issue. If the highest you see is 13.8 -14.2 Vdc, then the alternator would appear to be working fine and the problem is probably dirty connections or a battery issue.

Also, in what way were you "running the taurus pretty hard" and is the battery properly secured? Maybe the battery bounced around too much and broke a connection internally that is making intermittant contact, or maybe the engine compartment temperature got too high for the battery and caused it to start to fail.

-Rod

[brokenantimatter]

hmmm?

No better make it a long one

hmmmmmmmmmmmm?

I would check the connections going to and from the Alternator and Battery then I would check the battery. If all that appears okay I would start suspecting the alternator.

easiest way to check the alternator is with a digital voltometer and your on board tach but it alot of chain auto part stores can use a bench mark tester to check all parts of the alternator and usually for free.

[baldhead]

thanks for the tips guys.

Rod in answer to your questions yes the lights brightened outside their normal range. yes they cut out and came back on minutes later , and bulbs are fine. just driving hard as in follwing a car of friends to the E.R.

I stopped at discount batt. is fine alt. shot. Replaced the alt. now the batt. indicator light won't shut off but discounts code reader says no codes. Stopped at ford they said the indicator might just be due to low charge on batt (they also checked batt. and alt.) and once charged should go away.

[way2old]

Are you sure all the wires are securely fastened to the alternator? Sounds like one is loose that controls the light.

[shorod]

I'd suspect a loose or missing connection as way2old suggested as well. A weak battery should not cause the charging system light to come on, unless the weak battery is left for too long and it burns out the alternator (stator circuit just needs to see at least +5Vdc).

-Rod

[brokenantimatter]

I didn't notice that it said 2200rpm is when this happened -_-;

It might be the voltage regulator on the alternator and when it surging causes itself to shut down maybe?

[baldhead]

I forgot to say the day i started fixing stuff it got progressively worse like down to 1500RPM. Also after my car has sat for a few hours(since repair) the batt. light shuts off. And I found out my high beams burned out.

[shorod]

Which engine do you have, or better yet, do you know if your alternator has the internal or external regulator? I may be able to pull the wiring diagram to let you know which wires need to be connected to it.

Have you made any voltage measurements on it yet?

Have you checked to make sure all the connections are clean and tight?

-Rod

[baldhead]

Hey Rod it's a 3.0 GL. It was fine for a little while, but on my way home tonight the lowbeams got bright(even though my highs are burnt out)and I lost power steering about 1.5 miles from the house. Will get a voltometer tomorrow. Did I mention I did put in a reman. alt.

[shorod]

If it's the 12V and/or FFV Taurus, it appears you should have 5 wires going to the alternator, the large one (B+) from the fuse panel, a white with black tracer going to the S (Stator) connection in its own connector, and three wires in a connector, Orange with light blue tracer (A), the other end of the white/black S wire, and a light green with red tracer wire (I - indicator).

If you have the 24V Duratec, you should have the same connections sans the two ends of the S wire (white with black tracer), ie: 3 wires connected.

The A wire (orange/light blue) wire is protected by fuse 26 (30 Amp) in the engine compartment fuse panel. You may want to double check that fuse.

I should add the caveat that the above descriptions are taken from the service manual for a 1998 Taurus and therefore you may find you car does not match exactly.

-Rod

[baldhead]

Thanks it will be fun I'm probably gonna get a new batt. like I said the ford guy said it had 110 out of 550 cca. And was probably screwed from the bad alt.