aight guys, my 71 will not keep a charge. I've replaced the alternator, voltage regulator, battery, battery terminals, cleaned where the ground goes. what else is there that could be a problem? It's acting like the alternator is bad, but i took it back and they checked it out and said it was good. whatever is causing it is slowly draining down my battery until it just cuts off when i stop moving and go to crank it up and it does nothing. so what do y'all think is up?
Next thing you do is test for the drain. This is done by measuring for current drain between the battery and the cable with the cable off it's post. Since you don't know how heavy the drain is, you have to start by assuming it is high. A 12 volt bulb can be used to start with like a tail lite bulb. If it lights up to some medium to high level you can assume the draw is high and proceed to disconnect and sectionalize the cause. If the lamp hardly lights then the drain is much less. Sub a bulb of smaller size that takes less current to light it and proceed to isolate the cause same as before. Finally you need to test the charge rate with either a meter or a test bar LED device to see what the charging system is doing.
my "exciter" wire came loose from the alt. check to see if you have power to the alt. with switch "on"...frank...
i had the same problem with the surburban but it fixed itself or maybe it was the contacts or maybe itwas just because it was a POS chebby good luck
There's another way to check for a drain. It's a bit time intensive, but is a good proven way to narrow down the area of the problem. First, you'll need a muntimeter that shows DC voltage. A digital one is easiest to read, but an inexpensive analog works also. Set the meter to DC in the 20 volt range. Place the test leads on the battery and start the car. You should be reading over 13 volts with no equipment on at idle. Next, shut the car off and see what the meter reads. A charged battery should show about 12.5 volts or so. With the meter still attached, pull one fuse out at a time and see if your voltage increases. Where the voltage increase shows will likely be the area you should concentrate on checking for a dead short or open circuit. You can also do it with the vehicle on and sometimes this shows better than off.
Another (similar) way to check for drain: I spent the day with the motor off, positive cable off the battery, and voltage tester with negative lead on the battery cable, positive lead on the positive battery post. Set volt/ohm meter to 15 or 20 volts DC. Engine off, should read zero. Mine read 10volts, and found that it dropped to zero after pulling the dome-light fuse. Of course, it took all day because I checked the voltage regulator, starter, alternator, and every wire under the hood first.
yea like the first guy said get you a cheap test lit at any parts stoe like 2 bucks , pull the neg cable , put the alligator clamp on the cable end , an get a pair of vice grips an clamp on the neg post , if you got a draw -- the lit will lit up ( make sure car is off an all added acc. are offed )now remember if you got the door open , it will lite up the test lite , so push the switch in an see if the lite goes out. then start pulling fuses one at a time if the lite goes out , that circuit is the draw, real easy to do !!!!!
