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Ok, Initially I was going to write about how happy I was that I (with help of a mecanic friend) had finally solved my electric problem. Battery Draining when car was parked. I'll spare you the details of that story and save some room here.(you can check it out on my website under link, then journal.)

Short version. Did a lot of digging. Found the problem. Got the car back last night. Worked great. Parked if for 10 hours. Car started great this morning. Didn't take it to work though. Went home on lunch hour meaning the mustang sat for 5 hours. Went to start it. Battery is dead again. Guess I'm going to have to put my thinking cap on again. Not really a question. More of a sharing.

But does any one have any suggestions?
Here's what I have done
Changed alternator
New battery ground to the engine
New wiring from Alternator to Voltage regulator
and some Circuits that where bad have been changed
(not sure what he meant by circuits...but he changed them!:)
He also said He taped into the coil and bypassed the wiring under the dash.

Funny when you think you've solved it...it kicks you in the but! lol
 

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You do not indicate that the solenoid has been replaced. When I had weird problems similar to what you describe I found that my alternator was toast so I replaced it. Then problems came back again. I bought a new solenoid for about $16 and the problem went away. I am in no way an electical guru (in fact the whole electrical thing scares me) but what I did solved the problem so take it for what it is worth.
 

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You've bought too much stuff already! Start using your brain instead of your wallet!

Lift positive battery cable, connect 12 volt light (or test light) between positive battery cable and the solenoid connection where the battery cable connects:

BATTERY > LIGHT > STARTER SOLENOID BATTERY CONNECTION

Does the light illuminate (or glow) with everything turned off? If it does, your battery will go dead even with everything off.

If it doesn't illuminate, use a multimeter as a replacement for the test light, and connect it the same. Select amps or milliamps and see if there's any current indication. If there is an indication of current, then the battery will go dead over time.

What to do if the lamp illuminates. Disconnect the alternator. Does unplugging the alternator cause the light to go out? If it does, the diodes in your alternator are bad. New alternator time! If it does not, then you haven't found the problem yet. Plug the alternator back in.

Disconnect the starter cable. Does the light go out? If it does the starter solenoid is bad. If it does not, disconnect other wires at the solenoid to see if one of them is causing the short. As a last measure, unbolt the solenoid and see if the short goes away (light out), if not reconnect the starter cable and solenoid wires and look elsewhere.

Disconnect the regulator. Does the light go out? If it does, the regulator is bad. If it does not, reconnect the regulator and look elsewhere.

Disconnect the light harness at the firewall. Does the light go out? If yes, there is a short under the dash somewhere. If no, reconnect the harness and look elsewhere. Repeat for any harnesses connected between the battery and the firewall. Answer the same questions.

If both (one or more) harnesses are disconnected from the firewall and the light remains on, then the short is in one of the harnesses you've just disconnected. If not,

Plug the harnesses in one at a time and find out which is causing the short. Once you know which one is causing the short, then you have to use a schematic and trace out each wire that passes through that piece of harness.
 

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Excellent posting. You covered the exact procedure for troubleshooting for the possible causes of battery failure that most mechanics do not follow today.

Jeff
 
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