1999 Mercury Mountaineer

vehicle was totally dead this morning. I gave it a jump, and while i was still in park, turned the wheel and it started vibrating like crazy. I thought that maybe the alternator has gone out, and it is somehow affecting the power steering. What do you think?

I don’t see why the alternator would cause the steering to vibrate, especially one that has no output. Unless you left something on that discharged the battery there may be a parasitic discharge going on. You may want to have the charging system checked out for a problem.

A battery can function fine one minute, and then totally die the next.

But here’s what you don’t want to do. If the battery has totally failed, you do not want to jump start the engine and then let the alternator try to recharge the dead battery. This will cause the alernator to run hot causing damage.

So either try to recharge the dead battery to see if it’ll take a charge, or replace the battery. After that happens, then it can be determined if it was a battery issue, charging system issue, or a parasitic current draw issue.


I can’t think of any way the alternator could affect the power steering. It could be a characteristic of the vehicle you never noticed or otherwise a fluke. This type of thing is usually caused by the high pressure hose being mounted to or in contact with a part of the vehicle that can telegraph it to the driver. The fluid can start to pulsate through the hose, causing a pulsating vibration. Turning the wheel while the vehicle is not moving causes the power steering to work very hard, and that can intensify the effect. A lot of Chrysler minivans made in 2002-2003 were covered under a voluntary recall for this very problem. Get your battery and charging system checked out and see if the car continues to vibrate. The two problems should not in any way be related.

A quick way to check the battery and alternator is to use a voltmeter on the battery terminals.

With the engine off, it should read ~12 volts (much lower than that means the battery needs replacing). With the engine running, it should read ~14-14.5 volts. If it does not increase or drops off, the alternator/charging system is not functioning and should be checked out.

your serpentine belt, which runs the alternator, water pump, power steering, and a/c compressor, might have broken. Easy thing to check