Over the past few days, I've noticed the voltage readout has jumped intermittently for a few seconds. It usually would run between 14.0 and 14.4, but over the last few days, it has went as high as 16.9. When it did this, I stopped and pounded on the alternator. When i started again, it seemed to stay with in the 14.0 - 14.5. I took it to Advanced Auto to have them check the battery and alternator. The battery tested bad, so I replaced that. The alternator tested good. I drove home with the new battery. It seemed like all was well again, but then it spiked up to 15.4 for a few secs and then back to 14.4. I had them check the alternator a second time... still checked out good...

My questions are as follows:

1. Is there anything else besides the alternator that would cause this.

2. What is the highest voltage it should read.

3. Are there additional safeguards if it would run countinuously in the "red" zone ( past 16.5 i found out ) (ex. will a fuse blow if the voltage gets too high to protect any part of the electrical system ). I'm mostly worried about the digital dash.

I am planning on driving it down to Bowling Green on labor day and would hate to have anything "unexpected" happen as a result of these intermittent spikes...

Thanks for any help.


[Modified by steves 84, 2:14 AM 8/27/2002]

 

1.) Yes. Bad connections, and it's common.

2.) Should never read over 14.2 V

3.) The battery is the save-guard, but if the connections to the battery are shot, GAME OVER.


Check your connections to the battery. Press the bolts out of the battery cables and inspect (they come right out with a slip jaw plier). If any former battery aout gassed or flowed acid from the positive terminal (most often); not only is the connector shot, but the cable has probably sucked acid. Then you must replace the cables as well. If the battery bolts are shot, replace.

Also if the above is not true; check the ground connections for your block and chassis. Check the hot connections under the battery (windshield drain drops water on some connections if clogged or mis-routed.

I think you will find your problem in these areas.

 

Your alternator has a defective voltage regulator in it!!! Voltage excursions to 16.5 volts is 1/2 volt above the maximum tolerance on the voltage range specifications for alternators. About the only problem this will cause will be very high charging current and additional heat generated in the alternator which will shorten its life. All of your electrical equipment will be ok but this high voltage if it stays there will shorten their life also, light bulbs, radio, etc. I would either install a new regulator if you are up to taking your alternator apart, or easier, install a new alternator.

 

Other option could be that your dash is going flakey. Have you checked the voltage with a meter, or just rely on the dash? I know mine "freakes out" every once and a while. I need to get it fixed. Just one more thing on the list.....

 

The dash did "flicker" a little bit and got dimmer when it was doing it's voltage surges... God I hope it's not the dash... Although an 85 dash with the bigger numbers would be cool... :lol:

My first suspect is the voltage regulator also. I noticed the other night while driving that both the dash and headlights would brighten and dim just a little bit at the same time... The good ole advanced auto machine didn't flag it either time, but it could be in the beginning stages of failure. The guy even said that 14.8 was the best reading, which I think is High...

The battery I just replaced today was originally installed in 1999. I didn't look closely at the cables. I did not notice any type of build up on them the last few times I disconnected them though..

I just looked through my old paperwork and found out that I had the alternator installed back in May of 2001. What I didn't realize until I found this was that it Firestone has a 2 year 24,000 mile warranty on it. :D I have 4,416 miles left on the Warranty.... I'll have them re-check the alternator and may "force" them to change it anyways.... Only thing I'll have to pay for is the labor....

Thanks for the responses...


[Modified by steves 84, 3:24 AM 8/27/2002]

 

*** UPDATE ***

I just got a call back from Firestone. They had the Alternator hooked up to a machine checking the Voltage coming out of it. They said that the car read out did go up over 15 one time, but the readout on their machine stayed a consistant 14.06 volts....

Looks like it's either the bad connection or :cry :cry The Dash is going. :cry :cry

Any other options???




[Modified by steves 84, 8:23 PM 8/27/2002]