Help!! Battery light on dash came on???

JeffreyNMemphis · 12-05-2007, 07:15 PM

Hello Pelicans,

My car has been running fantastic. I have not turned a wrench on it in months, except the oil changes. I am on a trip to Decatur, Illinois, 400 miles from home, and my battery light came on.

I believe the problem was caused by the freezing cold weather. Snow was on the car and the windows were frozen shut. When I started the car, the light stayed on.

I have to drive 400 miles back to Memphis in the morning. If the battery is not charging, I am going to be in big trouble. Is there anything I can check or change, cheap and quick?

paulgtr · paulgtr's Garage

it means your alternator is not charging your battery.
and your alternator is mounted in the fan.
not exactly the easiest to get to.

scottb · 08:19 PM

The first thing to do is check that the fan belt is in place. If it snapped, you should not drive the car until it's replaced.

Otherwise, I'm afraid you have to start troubleshooting the electrical system (alternator and its internal regulator). Even if the belt is in place, I wouldn't drive the car until you know what's going on, or you risk getting stranded. You obviously have access to an internet connection. I'd start searching for local help. Is there a local P-car mechanic who can check the charging system for you? Is there a nearby PCA chapter where you can get a referral to a reputable mechanic? Are there any local Pelicans nearby who can lend a hand?

Good luck. Keep us posted.

madmmac · madmmac's Garage

First, you want to check your belt to begin with....loose/broken.

Did the light come on while you were driving it with the revs up or did you just start it after it was cold and let it idle?

Head416 · Head416's Garage

Quote:

Originally Posted by scottb

The first thing to do is check that the fan belt is in place. If it snapped, you should not drive the car until it's replaced.

+1 From what I've heard if your fan isn't spinning you can burn up your engine before your oil even gets up to temp. Not sure if it would really happen that fast, but it's not worth the risk.

Assuming your belt is in place, start by checking to see if it is loose. Try to turn the fan by hand - it should move just a little under the pressure of your hand then spring back into place. If you can turn it with anything less than all your strength, I'd be concerned, and tighten it up. Be careful if you don't have an extra belt, I've ruined one before by messing up the install.

If that checks out (and even if it doesn't), use a voltmeter to measure the charge on your battery. By searching on this site you should be able to find appropriate voltages for the battery when the car is off and when the engine is at a certain RPM. (For example, 13.5 volts at 2,000 RPM ***I made this up, don't use these numbers****) The results from these tests should help indicate whether it's the alternator, voltage regulator, etc., or even better, maybe that everything is fine!

When my alternator died, the battery light had been on and off for a couple days. I thought it was okay , just a little low, until the radio suddenly quit on me while I was driving on the freeway, car died about ten minutes later. In my case my battery was just a little under the recommended voltages both when off and at whatever RPM the test recommended, and I figured it was close enough. Oops. I'm sure it won't be the last stupid thing I do.

Good luck.

RussR · 12-06-2007, 03:49 AM

drag cars manage it for short bursts, no cooling or radiator. i can't imagine a short trip to the mechanics will damage it, especially if it's as cold as it sounds.

justinbaldwin · 04:07 AM

I have had intermittant alternator light problems ever since i bought my car five years ago. at first it was a reliable indicator that the battery wasn't charging. this happened whenever i left the car for a couple of weeks during winter and didn't use it.
i discovered that by driving over a pot hole, and/or giving the engine a decent throttle blip, something seemed to fix itself.
then one day on the way home i took no notice of the red light because of this intermttant nature of the problem. about twenty minutes later i got home to discover that the fanbelt had broken and my engine was absolutely baking hot, to make matters worse i had been blipping the throttle to 'unstick' the problem as in the past.
i don't know how close i came to melting my engine but must have been very close, this problem is compounded by all your instruments going a bit crazy when the battery starts losing power. So when the oil temp gauge suddenly went to the top of the gauge i ignored it!!! never again, i now carry a spare fanbelt in my car, and if you do this make sure you have the porsche fanbelt spanner too, because you can't do it without this, and no automobile rescue service will have one either. and while we're on the topic, make a note of the correct groove for your fanbelt while it's working. as many cars have had the compressor belt removed, and i discovered that the dealer i bought the car off had put the fanbelt on the wrong groove, i only discovered this when i tried to fit the new belt in the same groove and it kept coming off, as i couldn't adjust the tightness any more, once i realised his mistake it all worked nicely.

my light continues to cause problems. i rebuilt the alternator, but that made no difference, but recently i seemed to be able to fix it by taking the instrument dial out of the dash (very easy, just pull on SCs) and cleaning all the contacts behind, they were filthy from 25 years of use.
both my oil light and charger light still play up occasionally, for instance sometimes neither of them will come on when i turn the key, or they might stay on when the car is running, for the most part i now ignore them, as the battery is clearly not running down, and i know that there is plenty of oil in the car.
however, do not ever ignore your oil temp gauge, the way i did. that is the main lesson i learnt from all this.
good luck
justin

JeffreyNMemphis · 12-06-2007, 05:18 AM

Hey guys,

My fan is turning, the belt looks good. I have a volt meter with me, and I will check the voltage with the ignition off and then with the car running. If the voltage is 12.7 ignition off and above 13.5 with the car running, can I drive it?

Head416 · Head416's Garage

I'm really not qualified to say, but it sounds reasonable to me. I tried searching for the numbers but have been unsuccessful. I think if you've got a charge of 12.7 with the car off after it has been sitting then it sounds like you're getting a good charge.

Another test would be to check the voltage with lights off, car running, then turn them on and compare. If there's a big drop that's a concern. Spikes are also bad. Again, I haven't been able to find the numbers to go with the test, but maybe somebody will chime in.

bluesky · 12-06-2007, 10:51 AM

Jeff, Are you sure that your battery is not just at the end of its life and is just not accepting a charge because of the cold conditions?

I'd take the battery to an Autozone, have it checked, and see if it a cell has dropped out and is just not charging.

To me it sounds like the cold sapped your battery and you just need a new one....

Mr.Puff · 12-06-2007, 11:03 AM

Ugh, I'm in the same boat.

Wavey · 12-06-2007, 11:07 AM

Sorry I didn't see this yesterday. If you're still in a jam, there's a guy between Decatur and Springfield. Never worked with him, but I understand he does overflow work for Isringhausen, the P-car dealer in Springfield. Contact info:

John Vogel, Route 54, Chestnut, IL 62518 1-217-796-3500 Shop 1-217-674-3551 Home On 54, exit off 55 @ Springfield, near Clinton.

MORGANR770 · 12-06-2007, 11:20 AM

justinbaldwin,

If you find the alternator / VR need service don't panic. I am a moron and I had no trouble pulling the alternator out and replacing the VR. I worked from tech article I took from our host's website and it was really no big deal. Take your time, have a beer now and then and enjoy the process.

MORGANR770 · 12-06-2007, 11:22 AM

sorry should have addresed my post to JeffreyNMemphis. Hey it isn't easy going thru life inept.

NE Ohio 911 · 12-06-2007, 03:43 PM

Don't forget to check the transmission ground strap. Could be a bad connection due to the extra crud on the roads. I have learned this the hard way.

JeffreyNMemphis · 12-06-2007, 06:17 PM

Hello Pelicans,

I checked the voltage with a multimeter. I got a reading of 11.08 with the car turned off, and 10.66 with the car running (no lights or accessories on).

I called Memphis Motor Werks and they said it sounded like the alternator crapped out. They found me a Bosche authorized service center in Decatur, which turned out to be 2 miles away. The name of the place is Rainbow automotive, and the work on Mercedes and Porsche. The guy who runs the place said there are not many Porsches in Decatur, but they work on a small number of loyal customers cars. Unfortunately, they do not stock alternators and I will have to wait till the part arrives and they install it.

I am shooting (photographer) a wedding in New Orleans tomorrow at 6pm. The bride is one of my fiances co-workers and dearest friends. When Cindy found out I was dropping my car off for repair, and that the part was not available until tomorrow, she went (*$#^$%(*&%*%#%@%!!!!!!!).

I solved my desperate scheduling issue by buying another car today in Decatur and drove it home to Memphis. I picked up a 1973 Mercedes Benz 280SEL 4.5 sedan with 59,000 miles. Made the drive home with no problem. Tomorrow morning I will be back on the road and will make it on time to shoot the wedding.

ZOA NOM · ZOA NOM's Garage

Quote:

I got a reading of 11.08 with the car turned off, and 10.66 with the car running (no lights or accessories on).

That's a dead battery. You may not be able to resuscitate it after fixing the alternator.

Nice job on the emergency backup car.

MORGANR770 · 12-07-2007, 06:19 AM

Love the Merc ....most everyone on this site will think that is a good decision and me included.

The ground strap suggestion made by NE Ohio 911 reminds me that the ground strap being loose on my car is most likely what took out my VR in the first place. Definitely check that ground strap. In any case it should get regular maintenance even if it is not the culprit.