Engine to Battery Size Reply #15 – August 29, 2009, 01:05:34 AM Quote from: 85bird;288685Update:The battery was bad. So it was replaced. The alternator was good. I drove the car Wed, Thurs, and Friday morning it was dead again. uuuggghh.First off, you should have a couple of inexpensive tools.A digital volt meter and a basic incandesant bulb type test light.You don't say if the alternator was tested to see if it is charging while in the car or if you took it out of the car to have it tested.The alternator can be good but not being "turned on" by the voltage regulator when in the car. The voltage regulator must first be "turned on" by the ignition switch.Does the battery light come on with the ignition in run before you start the car and go off after it starts?This indicates the alternator is turning on. Assuming this is not a TC with an ammeter instead of a battery light.The voltage across the battery should go from 12v with the engine off to 14.5 volts with the engine running if the alt. is working.To check for battery drain with everything off as described by Watchdevil above:Disconnect the negative battery cable and hook the test light between the cable and the negative battery post.If it lights you have a drain.Track down the drain by disconnecting stuff until the light goes out. Quote Selected
Engine to Battery Size Reply #16 – August 29, 2009, 01:36:06 AM Quote from: softtouch;288767First off, you should have a couple of inexpensive tools.A digital volt meter and a basic incandesant bulb type test light.You don't say if the alternator was tested to see if it is charging while in the car or if you took it out of the car to have it tested.The alternator can be good but not being "turned on" by the voltage regulator when in the car. The voltage regulator must first be "turned on" by the ignition switch.Does the battery light come on with the ignition in run before you start the car and go off after it starts?This indicates the alternator is turning on. Assuming this is not a TC with an ammeter instead of a battery light.The voltage across the battery should go from 12v with the engine off to 14.5 volts with the engine running if the alt. is working.To check for battery drain with everything off as described by Watchdevil above:Disconnect the negative battery cable and hook the test light between the cable and the negative battery post.If it lights you have a drain.Track down the drain by disconnecting stuff until the light goes out.I have a volt meter that is not digital. It is new, and has numerous settings. I also have one of those test lights. SWEET.Good point, the alternator was tested while on the car. The battery light does come on and then go off as normal. The “dummy” light is working.Great. I will attempt to narrow this thing down. I appreciate all of the responses and help. You all rock.EDIT: Ok, I just went out and and did the test light test. With the pos connected I touched the tip to the neg and the clip to the cable. The bulb light up like a flashlight. So tomorrow, I will have my wife hold the test light in place while I pull fuses. She's gonna be so happy. :crazy: I'll just put a beer in her other hand and it will be a perfect situation.I have learned something today. THANKS. Making progress. Nice. Quote Selected
Engine to Battery Size Reply #17 – August 29, 2009, 09:02:59 PM UPDATE:I did the test light thing... pulled every fuse and such down there. The light never turned off.Any suggestions on what to try next? Quote Selected
Engine to Battery Size Reply #18 – August 29, 2009, 10:06:45 PM if your interested in fixing this,,read http://www.foxtbirdcougarforums.com/showthread.php?t=19254undo pos batt cableclip onto pos batt cablehose clamp your light to pos batt postlight on? unplug the alternator connectors one by onelight out?if not,,,,,proceed....reconnect alternator undo all secondary ring lugs on the starter relaylight out?one by one, touch each starter relay wires to starter relaywhen light comes on , jot down that wire color.You might find your replaceable voltage regulator is partially bad. Quote Selected
Engine to Battery Size Reply #19 – August 30, 2009, 01:19:20 AM There is no need to move the light to the positive battery cable.You can do all that stuff jcassidy suggests with the light where you had it. Quote Selected
Engine to Battery Size Reply #20 – August 30, 2009, 01:34:37 AM the only reason i mention the pos side is because many sub assemblies on the cars have a ground of thier own not dependent on the battery.if i remove the pos cable, i have more control over the input power and to identify which circuit by taking away its power.just be glad this drain you have is large enough in ampacity to light up your test light. try chasing a few millivolts of drain around. Quote Selected
Engine to Battery Size Reply #21 – August 30, 2009, 01:37:24 AM Quote from: jcassity;288918the only reason i mention the pos side is because many sub assemblies on the cars have a ground of thier own not dependent on the battery.if i remove the pos cable, i have more control over the input power and to identify which circuit by taking away its power.There are no grounds independent of the battery.All current flow must go through the negative battery cable. Quote Selected
Engine to Battery Size Reply #22 – August 30, 2009, 01:42:01 AM I'll see what I can done on that. Thanks again! Quote Selected
Engine to Battery Size Reply #23 – August 30, 2009, 09:22:01 PM naw,, there are plenty of grounds under the hood in addition to the the battery neg. proof is ,, how is it your car will run with out a battery hooked up?,, because it is bonded to the frame below the battery.example would be the TPS,, its ground is obtained from the engine harness which ties to the heads as well as the firewall.many parts have ground unto themselves isolated and not depending on the battery ground. Quote Selected
Engine to Battery Size Reply #24 – August 31, 2009, 12:13:36 AM Quote from: jcassity;289017naw,, there are plenty of grounds under the hood in addition to the the battery neg. proof is ,, how is it your car will run with out a battery hooked up?,, because it is bonded to the frame below the battery.When the car is running the alternator is the power source.When the car is not running the battery is the only power source and all current flows through the battery.Quoteexample would be the TPS,, its ground is obtained from the engine harness which ties to the heads as well as the firewall.many parts have ground unto themselves isolated and not depending on the battery ground.Maybe it would help if instead of calling it ground we called it the negative side of the power source. The engine block, heads and chassis are all part of the negative side of the power source.In an electrical circuit(derived from circle) the current travels in a loop. The current goes from the positive of the power source through wire to the load, through the load, through the chassis/ engine block to the negative of the power source, through the power source to the positive of the power source and out through the wire again, and round and round it goes.When the battery is the power source and you disconnect the negative cable the current can't get back to the negative of the power source and all current flow stops. Quote Selected
Engine to Battery Size Reply #25 – August 31, 2009, 01:16:17 PM Quote from: jcassity;289017naw,, there are plenty of grounds under the hood in addition to the the battery neg. proof is ,, how is it your car will run with out a battery hooked up?,, because it is bonded to the frame below the battery.example would be the TPS,, its ground is obtained from the engine harness which ties to the heads as well as the firewall.many parts have ground unto themselves isolated and not depending on the battery ground.Actually the TPS and all other sensors are grounded by the EEC which in turn gets it's ground from the chassis... If you measure the ground on the TPS sensor to block, chassis, or the battery you likely find there is a .1v or more difference... This is why TPS voltage should be measured across the sensor and NOT to the engine... This is why setting the TPS at .99999v and using the engine block for ground will give a false voltage reading... Quote Selected
Engine to Battery Size Reply #26 – August 31, 2009, 04:47:15 PM For all of you nonbelievers out there, here is a little experiment you can try:With the negative battery cable disconnected (engine not running of course) put a test light between the positive battery post and any grounds you think may be good ones. Does it light up?Let us know what you find. Quote Selected
Engine to Battery Size Reply #27 – August 31, 2009, 05:29:56 PM You should not get a light. I don't need to check. And if you do, Send me some of your smoke! Quote Selected
Engine to Battery Size Reply #28 – August 31, 2009, 10:18:14 PM Quote from: softtouch;289134For all of you nonbelievers out there, here is a little experiment you can try:With the negative battery cable disconnected (engine not running of course) put a test light between the positive battery post and any grounds you think may be good ones. Does it light up?Let us know what you find.With a small enough current bulb you can have a light(but you won't find a test light with that low of current draw bulb)... My TC draws about 20ma with everything off... Quote Selected
Engine to Battery Size Reply #29 – August 31, 2009, 10:49:49 PM Quote from: softtouch;289134For all of you nonbelievers out there, here is a little experiment you can try:With the negative battery cable disconnected (engine not running of course) put a test light between the POSITIVE battery post and any grounds you think may be good ones. Does it light up?Let us know what you find.Quote from: TurboCoupe50;289191With a small enough current bulb you can have a light(but you won't find a test light with that low of current draw bulb)... My TC draws about 20ma with everything off...Reread my post.Just trying to do a little DC electricity class. Quote Selected
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