Greetings, I've got a 1980 245 with a B21F and M46, about 178K on the odometer. Yesterday the car worked perfectly. This morning, I went outside to start it, and it was completely dead; I would get a few dim bulbs inside the car, but it wouldn't even turn the engine over, and when I turned the key, everything died. Typical dead battery, I thought. So I popped my clutch and drove to work (20mi) without issues. However, when I arrived at work, I attempted to restart the car after that long recharge drive, and everything went dead again, as if the battery hadn't charged at all on the drive. Again, car was fine while driving, my voltmeter read in the middle like it normally does. I assume it can't be the alternator, considering once it starts, it's fine. I checked the connections between the alternator and battery, and everything looks normal. If it were a short, or seized starter motor, wouldn't a fuse have blown somewhere? My battery is about 5 years old, so it seems the obvious culprit, but can a battery go completely bad overnight? Yesterday the car started fine, turned over quickly like normal.

What are the possibilities? Thanks!

Well I cleaned the contacts, jump started the car successfully, but the battery never charged. I went ahead and replaced it, and everything seems fine now. I'll probably have the old battery tested just out of curiosity, but the new battery seems to have fixed the problem.

I had exactly the same thing happen once. Car ran normally the day before. Went out in the morning---dim dash lights, no response from the starter. Got it going by coasting down the hill and popping the clutch. Charge light went out as soon as it started. Drove straight to the battery place and had them test it. Was told the battery was shorted internally. Bought a new one, no further problems. At the time, I lived at the end of two miles of bumpy dirt road, so that may have contributed to its early demise. Don't recall how old the battery was.

I agree with other posters, especially about the battery connections, which can sudeenly stop conducting because of invisible corrosion.

And here is an entirely different idea. Recharge the battery and use a multimeter to see how much current the car draws when it is parked with the engine off.

I suggest this because my '86 had a short in the door lock circuitry that repeatedly drained the battery while the car was parked, without blowing a fuse, but which led to no problems once the car was running. This seems unlikely as you seem to have had no charging going on at all, but if all else fails, might be worth looking for some kind of unexpected drain on the battery at beofer you shell out for a new one.
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jds

The starter is quite robust on these cars, it rarely fails.

I had a K-Jet 81 that died from loose battery connections, so check that, but the car will run about an hour with a poorly charging alternator.

Alternator brushes, or the wiring in the engine bay will be the likely cause. If the wiring hasn't been replaced it may require attention soon.

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Stef (rewired harness, rebuilt Bosch 55 ampere alternator Interstate MTP-65 battery, speedo/odo converted to miles, scotia blue 81 245 B21A SU M46 3.91)

It could be all that complicated as BC and Sven's Maintainer predict, but again, it could be as simple as a loose battery terminal. Just a thin layer of lead oxide between the post and terminal will give you those exact symptoms; voltmeter looks good while running, runs OK, but lights dim or go out when trying to start using the starter.

Give the terminals a brush-up before taking the battery apart to measure individual cells or spending any money whatever.

"Just a thin layer of lead oxide between the post and terminal will give you those exact symptoms; voltmeter looks good while running, runs OK, but lights dim or go out when trying to start using the starter."

I remembered this problem from a scan this morning and was just about to post essentially the same thing — poor contact between the positive terminal "ring" and the battery post.

The alternator output is getting to the terminal — and back out the smaller red wire to run everything — but is not getting back into the battery to charge it up. And what little residual voltage is in the battery can't get out to power lights or anything for the same reason.

The problem may have been coming on over some time, not "overnight", and just now reached critical mess.
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Bruce Young
'93 940-NA (current), 240s (one V8), 140s, 122s, since '63.

The battery may not be completely dead, just dead enough to do nothing.

The cells have lead plates, and over time the lead oxide accumulates on them, and sometimes a little falls to the bottom. When there's enough in the bottom to short the plates, that cell dies. It cannot accept a charge.

A bumpy rocky-road ride with poor battery hold-downs can accelerate this process. BTDT Killed three cells.

Use a voltmeter to check volts across the battery terminals. Car running should be 13 to 14 volts. Engine stopped chould be 12 +/-.

See if your nearby AutoZone (or the like) will test your charging system.

There is a way to check if it's the starter. On the started are three terminals. One covered by a rubber boot, and two spade lug types. The one under the boot has two heavy wires, one from the battery and one from the alternator. That terminal is hot and ready to supply large amperage current all the time.

Of the two spade lug types, one has a brown wire, the other a yellow-blue. If a heavy duty wide tip flat tip screwdriver can touch the heavy wire terminal and the blue-yellow terminal, the starter solenoid should engage and the starter motor turn. There will be sparks. If you get sparks and nothing else, it is the solenoid.

I believe, because of the dim interior lights, that in your case it is not the starter.


Good Luck,

Bob

:>)

Needed a new pos battery terminal on my 86-245 400,000 mi "truck".
Sounds like you have the same symptoms.
Ken

I suspect a bad battery, but a bad starter motor (or connectons to it or the starter solenoid) is a possibility.

What does the dashboard voltmeter show when motor is not running? If it will give an indication of battery voltage without the assist from the alternator, that will show you what the battery's charge is.

If its wired so that is not possible, you'll need a voltmeter that will read the battery voltage off its terminals.

However, dim bulbs inside the car before starting is an indicator that there's weak voltage in the battery at that point. Based on that I too suspect a bad battery, but some testing with a voltmeter is worthwhile before spending money on a new one.

If you can muster the patience to test individual cells with a voltmeter, the procedure is here:
http://www.brickboard.com/RWD/index.htm?id=1020149

This will let you know if one or more cells is/are bad. If so, the battery is your culprit, and would definitely need replacing.
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DAMHIK: Don't Ask Me How I Know - - - Sven: '89 245. 951 ECU, open-front airbox, E-fan, 205/65-15's, IPD sways, E-Codes, amber front corner reflectors. 500 mi/week commute. '89 245 #2 (wifemobile). '90 244 (spare, runs).

Thanks for the thoughts, you're pretty much confirming what I suspected, except that I never had a battery go bad overnight like that, so it seemed strange. What I'm going to do is have someone jump start my car this afternoon when I leave work. That way I'll know if the starter works. If it does turn over with help from someone else, then it seems the battery is the issue. Any additional thoughts regarding the charging system from alternator to battery? What can go wrong there, if I know the alternator itself works?

I've seen cases where a drained battery will soak up charge for a good while before the two batteries together are ready to start the car. That is, the lame battery amounts to nearly a short circuit for the healthy one while it is charging, leaving little juice available to start your car.

So, if you want to test the starter by jumping the car, let the running car charge your lame battery for ten-fifteen minutes before you try cranking it. But understand that if your battery is bad enough (serious internal shorts), you may not be able to jump-start the car.

But I'd still check for corrosion or poor contact at the terminals as TwoFortyTom suggested - and check battery voltage across the terminals - before going any further.
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DAMHIK: Don't Ask Me How I Know - - - Sven: '89 245. 951 ECU, open-front airbox, E-fan, 205/65-15's, IPD sways, E-Codes, amber front corner reflectors. 500 mi/week commute. '89 245 #2 (wifemobile). '90 244 (spare, runs).

Good plan with the jumper cables. I think the problem cannot be the battery, because every battery I have bought was purchased in the month of October. It is still September.

OK, wait six days, then buy a battery...
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DAMHIK: Don't Ask Me How I Know - - - Sven: '89 245. 951 ECU, open-front airbox, E-fan, 205/65-15's, IPD sways, E-Codes, amber front corner reflectors. 500 mi/week commute. '89 245 #2 (wifemobile). '90 244 (spare, runs).

Absolutely. Never buy a battery in September. ;-)

I am with Sven that the most likely culprit is the battery.

You are asking for it if you keep jumping this thing (ever see a battery blow up?). Get it started, drive to a Auto Zone or equal and get them to test the Battery, (they will charge and discharge test). Then they connect an ampmeter and VOM and check the system, and they do this for free. Then you at least know for sure what is not working. Then you know what to go after more or less and you have wasted no coin for doing it.

Regards,

PT

I hope for your sake and your passengers and those on the road near you, you get some experienced technical help on that shimmy you suddenly developed. I was going to add to the post, but the brickster that explained the steering in "shin bone connected to the knee bone" fashion laid out the groundwork pretty well. I think you could have a very serious steering/suspension problem that could easily be life threatening. This is nothing to idly guess at.

Now for batteries and alternators, I do believe there are plenty of people who view Auto Zone clerks to be the experts in that arena.

Got all new Poly Bushings today, and have a buddy who does front end work or heavy trucks coming by to take a look and give an hand on Saturday. The wife and I are carpooling until then.