Battery (alive and then dead and then alive!) + starting problem

[Puka]

I've been having this strange problem -- I've posted a version of it before but this is slightly different:

battery, gen., volt. reg., starter and batt. cables and wiring that I can see test out okay. Car charges -- all good. Took it to a good electrical shop -- they say nothing wrong with it. (They work on old Buicks and had a 1950 Super 4dr they'd work on while I was there).

Anyway, here's the problem:

I'll drive the car for a while. Then park it. And only sometimes, if I try to start it again, the starter will crank but not enough to start the car. If I try it again, then the thing goes dead.

So I have the thing jumped, and drive it for 5 minutes. Shut it off, and then start it, and it is fully charged? How does that work.

Maybe this problem is only happening when the engine gets hot.

Maybe I need a thicker positive batt. cable? I have one on there from Bob's and it's for a 6v system. Maybe I should try to get an even thicker battery cable? Would that take care of the problem if the engine was hot and the starter had to work harder to get the engine to turn over?

Maybe I need a new battery?

Could it be the solenoid or the starter relay? If so, what exactly do these things do.

I am not really clear how the electrical system works. Anyone know of a good guide on the net to this? I just bought a multimeter from Sears and want to start doing my own testing and detective work on the system -- just to see if I can't get a reckoning of what's happening.

I guess the first thing I could do is get a new battery -- mine is an Exide that is about 4 years old and has been drained and recharged several times. Except whenever I've taken the car into the shop, the battery always tests okay.

You guys have been a great resource in the past, and I thank you for your help on this in advance!

Puka

<img src="http://www.aaca.org/ubbthreads/images/graemlins/confused.gif" alt="" />

[Guest Chrome]

My '49 does the same and it has new, well two summers old battery.. battery negative cable gets very warm when I start it. Maybe starter solenoid is going bad and it needs more power when engine is hot, or our engine timing is bit wrong.

I always laugh that my Buick orders me to take coffee break and come back later <img src="http://www.aaca.org/ubbthreads/images/graemlins/cool.gif" alt="" />

[Guest imported_bjr]

If your negative battery cable gets very hot, it is undersized or the connections on one of the ends are bad. A battery cable only gets hot when too much current is flowing through it in relation to it's carring capacity. The carring capacity can be compramised by bad cable ends or bad connections or being too small a cable to start out with. You may also have a starter that draws over 400 amps when hot, due to internal winding problems. In which case a bigger cable will not help. Hope this helps. Brian

[Guest brh]

I think the first place to start is the battery. If its 4 years old you will need a replacement soon anyway. But the question is--is the battery dead or does it act like its dead? Next time it does this hit your headlights on, then try and start the car, if the lights go out or dim dramaticaly, its the battery. If the lights dim but hold, you probably have a starter that is drawing too much current. If the lights don't dim at all and are fine, its a starter problem. Don't change the specs on your cables stick to what should be on the car. Just some thoughts.

[Ron Green]

bjr has pretty much hit the nail on the head with his suggestions. Now go spent $3 on one of those floating ball type testers and see how much life your battery has. They do work.

It also pays to check your own battery with one of these testers before you take it to a parts house for them to check it, after all they are in the business to sell parts.

[Guest imported_JPIndusi]

Try the following:

1. Remove both battery cables.

2. Inspect them carefully in good light especially around the clamp and ends.

3. Sand the ends and use a battery post tool on both the battery posts and the cable clamps. Be sure you have a bright shine to the metal.

4. Sand the bolts and locations where the cables connect to the block and the starter relay.

5. Be sure the battery cables are no smaller than 1 gauge, 0 gauge is better.

6. At four years old the battery is on it's way out unless it has been carefully maintained, that is, kept fully charged and clean.

7. If these do not cure the problem, you move to the starter and starter relay next.

Good luck.

Joe BCA 33493

[KAD36]

Interesting problem - definitely invest in one of those little electrolyte testers with the floating balls - all it takes is one bad cell to be a little low and drag the whole battery down. What you might have is one weak cell that can't hold a long term charge and pulls the whole battery down over time. The tester should measure equivalent specific gravity in all cells. Following the advice in previous posts is the right thing to do. If the battery and cabling all checks out, my next guess would be a bad or weak winding in the starter that is causing a sneak path to ground or breaking down when its hot, assuming the solenoid is engaging but the starter isn't turning, or not turning with even torque.

Good luck

[Guest Albert]

I had one like that a few years ago sometimes would start and sometimes not, it even had a new battery (2 months old) with both side & top terminals, with the leads hooked to the side posts. Found I could jump start my self going from the top terminal to the side post terminal, the shorting bar inside the battery was not always making connection.

[Guest Dans 77 Limited]

I had the same problem with a 71 Monte Carlo years ago and what my problem eventually turned out to be was the starter, when the starter got hot you couldnt start the car without jumping it , but when it was cool it was fine. As to what the exact problem in the atrter was , I dont know , all I know is I changed the starter and the problem went away.

Hope this helps

Dan

[JohnD1956]

Have you checked for the existance of, and condition of ground straps to the engine? Maybe they are corroded, or broken completely? I owned an MG once, which had a similar eratic starting problem. One day while it wouldn't start I brushed against the carb linkage ( which was a simple metal shielded wire like on old lawnmowers) and got a burn. Then we realized that a previous owner had not put the woven ground straps back in when the engine had been worked on. As a matter of fact, he gave me that car because it wouldn't start. A pair of straps and 10 minutes later it was good as new.

[Puka]

Thanks for all the help on this one.

Here's what I did: brought it back to the shop -- they checked it for several hours - found no problem. Didn't charge me. So I got myself a batt. tester and checked each of the three cells in the batt. One was no good. And anyway, as some of you have stated, batt over 4+ years is time to go.

Replaced it with an Optima battery (red top) from Advantage Batteries in Santa Monica, CA. Also replaced the poss. batt. cable with a new one. (0 guage).

Since the new battery is considerably smaller size, had to fashion a new hold-down harness.

Also noticed that one of the batt. tray bolts is missing. Anyone know off hand what size this is? Looks like 11/16 or 3/4 but not sure.

Anyway, started up the car, took a voltage reading and it was at 7volts. So I figured the damn volt reg. needed to be adjusted as I'd burn out the gen. armitature eventually, right? Tested it after driving a few miles and it was at 6.43 volts. Then measured it again another time, and it was at 7 volts.

Took it into the shop -- they tested it -- said it was fine.

Today tested the batt. output voltage yesterday and it was good at 6.43-6.49 - except I I checked with the Craftsman Multimeter set to VAC (with a max. 10Amps) and the Multimeter started smoking!

Anyway, will check the neg. batt. cable -- looks good on visual inspection -- though there's a lot of grease where it attaches to body of car -- though I suppose that's not bad?

[Guest brh]

Glad to hear you are on the road to recovery. Before you go messing with voltage reg, get the exact specs for the voltage output. I know 12 volt systems actually show 14 volts for output. I don't know how the 6 volt systems work. Also, check your voltage with the meter on VDC. A generators output will be direct current, alternators output is VAC-alternating current

[Guest Albert]

Each cell is 2.2v for full charge or 6.6 for a 3 cell battery, charging voltage is normally min 7.5v to max 8v depending on the temperature.

[Guest imported_bjr]

Just a clarification: Alternators do not put out alternating current to the battery. They have internal diodes that let only one half of the sine wave or current in one direction only out to the battery. Internally upstream from the diodes they do indeed put out alternating current, but you can't charge a DC battery with AC current, thus the diodes. Brian

[Guest brh]

I stand corrected, thanks. I always wondered how in the world a batter could be charged with A.C. current. Diodes make sense as it only allows current to travel in one direction, correct? Do you check output with VDC or VAC? Ya learn something new everyday.

[Guest imported_bjr]

You check output with a DC volt meter. AC is only available on the other side of the diodes, not on the output to battery side. There was a kit a few years back to make your alternator put out 110 Volts AC. It connected inside the alternator and had a switch and a 110 volt outlet on it that you could plug stuff into. I had one on my 1975 Dodge Power Wagon, I finally burned it up after about 3 years of use. The alternator was still good though. Brian