Hi there
Ive posted another message which helped get me to the point i am at now...I have seeemingly made some progress, but I am still stumped and I am starting to get really aggravated..
I am ready to drive this damn car off a cliff!!!

Here is what is going on now...

The car, when idling, will read 14.5 volts or higher...
As soon as I turn on the head lights, I drop to about 12.5 volts and the voltage steadily goes down...After I turn the lights off, the voltage will again jump to 13.8 or so and then slowly increase to the high 14 volt range..
If I turn on my blower and wipers on, the charge drops slightly, but stabalizes around 14 volts...
With no load on the battery, with it running if I increase the idle, my charge starts to drop(but I know my belt is tight!) and it continues to drop..(and god forbid I drive the car..Ill break down, with a dead battery)
I had the battery load tested and was told it was fine (I had it tested by 2 mechanics)
Yesterday, I started the car..(was a very weak start) but the battery read 14.5 volts, so I headed to work, only to break down about 8 miles down the road, and my battery read 10 volts....)

I can only conclude that the lights are causing me a problem..but I dont know why..all the fuses are fine and I cleaned the battery terminals and connectors...I also noticed that, when I turn my headlights on, which work, none of the lights on the rear of my car work...

Someone please help me before I find my sledge hammer and take care of the car once and for all!
Thanks,
Chris

P.S I just had my car running, reading 14.8 volts...I decided to pull my battery and charge it...The battery has been charging for an hour, with a 10 amp charger..and it still isnt fully charged...
NONE OF THIS MAKES ANY SENSE TO ME!

I think my car is finally fixed!!
Yippieee!!!

Im still a little afraid to use my radio or blower though!!!
That will come in time!! :)

simple sololution that I overlooked!

My battery terminals were not tightened down fully...
I cant believe that was the problem...But I just got back from a 50 mile cruise and when I got home...I shut the car off and started it again..

It started strong!!!! And I have 14.9 volts in the battery!!

Ill tell you though...I feel like an idiot for not figuring this out sooner!!


THANKS TO EVERYONE!!!!!! You are all wonderful!! If you ever want to go skiing in vermont..send me a message!!! :)

30 inches of fresh powder over the weekend and we are expecting another foot this weekend!!

the car has bad alt belts!the belts can be tight and slip because they are too worn to grip under load. they do not have to squeal either.

bob from pittsburgh

If you continue having the problems with excessive load from headlights,
I would check the headlight wiring for shorts.
--
George Downs, The "original" Walrus3, Bartlesville, Oklahoma

My guess and this only a guess is that your voltage regulator or brushes are braking down under load, I would try to replace that assembly. Also check the ground connection for the alternator and the large read wire which goes to the battery. A bad connection on either of those could give you the exact symptoms you decribe. I think the back lights are unrelated. AutoZone and i suppose some other parts store will test the charging/battery system for free.
--
David Hunter

Hey...thanks for the advice...
Actually, right after I wrote the message, I went outside and cleaned the wires going to the battery..(the red ones were destroyed)
Things seem to be going ok now....With everything on, I was running around 14.2 volts...But I wont believe it until i drive and dont break down..

Thanks!!

Hey Chris,
This may not help this time, but it's my best shot at explaining the basics for those with less experience. It's as brief as I could make it. Hope it makes sense. Comments welcome.
----------------------------------------------------
The Battery's main job is to supply power to the starter. Period.

Once the engine is running, the Alternator supplies power forEverything Else — plus a little extra to keep the Battery charged. (The Battery is just along for the ride at this point.)

In simple numbers, the Battery is capable of supplying no more than 12 Volts. The Alternator can put out about 14 Volts. (Anything over 12 Volts is what keeps the Battery charged.) A meter on the Battery terminals shows Battery voltage with engine off, and Alternator voltage when running. If it drops below 12V running, you're reading Battery again.

If the Alternator output falls below 12 Volts, the Battery starts taking up the slack (not its main job) and "running down". The fewer the electrical demands, the longer the running down will take. I once went about 40 daytime summer miles after leaving a wire off the (V8) Alternator.

Voltmeter readings can be misleading, however. For example, six flashlight batteries connected end-to-end will read 12 Volts on a meter. But they would hardly power your headlights, let alone turn the starter motor. They wouldn't have the "Capacity".

Alternators sometimes lack Capacity too. They may show 14+ Volts with the engine idling, but less and less as lights, fan, etc. are switched on. The usual suspects in this case are:

1 - The Voltage Regulator/Brush unit attached on the back of the Alternator
2 - Worn/grooved commutator (in the Alternator, where the brushes ride)
3 - Worn/Glazed/Loose/Slipping drive belts
4 - Poor connection(s), Alternator-to-Starter-to-Battery + terminal
5 - Poor "Ground" wire connection (between Alternator body and mounting bracket)

If the Alternator output never rises above the Battery's 12 volts, it could be due to:

A - More severe versions of any of the items listed above
B - Failure to "pre-exite" the Alternator's charging circuits (current flow from the Battery Light on the Instrument Panel via the thin red wire to D+ on the back of the Alternator.
C - An internal failure within the Alternator itself (least likely)
--
Bruce Young,
'93 940-NA (current)
'80 GLE V8 (Sold 5/03)
'83 Turbo 245
'76 244 (lasted only 255,000 miles)
73 142 (98K)
'71 144 (track modified--crusher bound)
New 144 from '67 to '78
Used '62 122 from '63 to '67

Thanks for the explanation...makes sense...

With the car running, the meter will read 14.5 volts (and seems to slowly rise..Ive seen it get to 15.5 volts...)
Ive checked all the wires..and they are all fine...
Ive replaced the voltage regulator
Ive replaced the battery...

I still cant seem to keep the car running...

Im bringing it to a mechanic in the morning...


I give up

and even with the car off...My meter will read 14 volts on the battery..

So I am thinking the meter is not reading correctly

That high reading is probably what's called a "surface charge", which can show on a freshly charged battery before it's had any demands made on it. (Especially if your Alternator is putting out 15 volts)

When the battery is put into use (or over a short time), this surface charge dissipates, and the battery level drops back to its nominal 12 volts. This initial drop is normal.

So I wouldn't necessarily blame your meter.
--
Bruce Young,
'93 940-NA (current)
'80 GLE V8 (Sold 5/03)
'83 Turbo 245
'76 244 (lasted only 255,000 miles)
73 142 (98K)
'71 144 (track modified--crusher bound)
New 144 from '67 to '78
Used '62 122 from '63 to '67

the problems are coming from one of these 3 things:
or battery
or voltage regulator
or alternator

or together (less probability)

The number of electrical consumers you put on together is not to the point!
whatever a mechanic may say (mechanic <> electrician -)° )

Point is that the battery has to keep it charge and that it is proper charged though the alternator, which seems OK, (because of the 14,8 voltage reading of the voltage regulator)

so only thing that remains is your battery: very bad state probably or premature wear, too less acid/water inside

================================
I suppose you have the bosch alternator = 55 amps
and your battery is around 60 Ah;

soo with the alternator running at full charging power it will take at least 1 hour of complete charging from no charge at all

but wehn car is running there some other electrical consumers which will drawn some of the charging current

================================

At 10 A charge; it will take 60/10 = 6 hours to charge your empty battery
================================


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My advice: try to borrow a battery of donor car and compare the behaviour...
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--
240 '88 B200K 260+kkm virgo,Phoenix Gold ampli, Focal door speakers, debadged, 6 rear red lights