This is ridiculous (1 Viewer)

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May 30, 2002
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Alright, im new to this whole automotive electricity thing so here goes. my battery, it doesn't work. i posted on here a while ago about a similar question thinking it was the alternator. well i thought it was had the alternator tested and they (autozone) said that it was "overcharging" and killing the batteries. so after some scrounging and several scrap alternators that turned up dead, i bought a new one. A new battery too under NTB full replacement warrenty. its been about a month, the damn battery seems dead now. I cleaned the wires, the posts, made sure all connections and wires were snug and nothing works inside the battery, no power at all. being christmas eve and all with everything closed for the next few days, what can i do. also, what could be causing this it was running fine up until this morning when i went out to start it. So what tests can i do to figure out what is causing this so it doesn't happen again. Thanks for the help

1969 FJ40 totally stock
 
ScarboDP,
I would wager more than a few cold beverages that the problem lies with the fact that you didn't replace the voltage regulator when you replaced the alternator. This may have been your problem all along. None the less, what can you do today. Well, if you are able to add water (Distilled) to your new battery....by all means do so as it will be all cooked out by now. If not, take it to NTB for a new one. An easy way to check if your overcharging is to put a volt meter on the battery connections and have a friend rev up the engine. Your vmeter shouldn't get above 14 volts. With an inoperable vregulator 16 to 17 and beyond may be seen. At this point you have either a new battery or were able to add precious water to your old one. No place open for a few days to get a new vregulator ...so one little trick that will use up some of that extra current and get you through for a few days is to run any and every electrical appliance on the truck. Lights, heater blowers front and rear, stereo if so equipped...I'd stop short of putting on the wipers though....I'd feel silly. That should get you thru untill you can purchase the new regulator.
 
your right i didn't replace the v regulator when i replaced the alternator. ill check it out and let you know what i find
 
i just had a similar problem with my 71 fj40. it would start and run fine with a fresh charge, but after a few starts it wouldn't turn over. i checked the battery and alternator, all ok. it turned out to be the starter. it was drawing 445 amps or volts, when it should only need 140 at most (chevy v8). replaced the starter and haven't had a problem so far.
 
okay now could you explain to me how i can test this stuff to in fact find out what is the problem. I have a digital multimeter, but im not real sure on how to test for it, im still new to this electricity stuff. could you be detailed, cause like i said im new to this stuff. thanks alot, and just a side note, i didn't know anything about cars or cruisers when i bought mine a year ago and now thanks largely to the help ive gotten on this website i have a little knowledge and a lot of confidence that i can take care of anything that happens on my cruiser
 
OK
Check the voltage on the battery as it sits. 12.0-12.5VDC is good. less than 11.5 is not. Recharge and start again.
Have someone crank the engine while you check the battery voltage. It's a real good idea to stand to the side as you do this as I have seen lots of my students try to start an unfamilier vehicle in gear. The voltage should not drop below 9.6V while cranking. If it does you have a bad battery, bad starter or bad connections.
Once the vehicle starts, you should see an increasee in voltage as the alternator takes over. 13.5 to 15V is good. below that could be a bad voltage regulator or bad alternator. Above 15V is a bad regulator and this will overcharge the battery and make it junk pretty quick.
Turn the truck off. Put the volt meter between the negative terminal and the block and crank. This measures voltage drop. More than .5V and you have bad connections. you can do this on the positive side too between the pos battery terminal and the starter stud.
If you have regulator problems on an old 40, you can pull the top off the regulator and try to clean the breaker points, they stick when they get old.
Don't trust new parts, especially aftermarket ones. If the test says it's bad, take it back and ask them to test it at the store.

Hope this helps
 
just ran the tests everything came out voltage wise within the numbers you gave once it started however the multimeter read 15.38 volts does this mean that the regulator is bad. Also are there any more specific tests that I can do to rule out the starter or the regulator. Thanks.
 
That's pretty high at an idle. Check it at 2000 RPM. if it's much higher than what you have, it needs a regulator.
For a real stater test you need an amp meter that can take 400+ amps.
For a good alternator test, you need a carbon pile load tester to get the max output.
A garage shouldn't poke you for much more than $20 for a charging system test.
You can try turning everything on and checking voltage at idle and at 2000 RPM. If it falls in the good range, it's probably OK.
The Cruiser uses a mechanical voltage regulator. Sometimes they stick occasionally. If your battery is showing signs of overcharging like being low on water or bulging out on the sides, that's a pretty good bet thats what it is.
 
Been gone for awhile, ScarboDp did you rev up the motor to the 2 grand range ? &nbsp:Did your voltage increase to 16 and beyond ? Since, AZ told you that your charging system was overcharging, I would focus on the vreg and alt. starters will kill batteries in a different way. Also, are you able to add water to your battery ? If your battery is dry and 1 month old, definitly overcharging.
 

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