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Discussion Starter · #1 ·
Any help here?
I drove my car a fortnignt ago and everything is going great. One week later I get ready for another spin and......Nothing happens, not even a click! I also notice the interior lights are all off when I open the door and the immobiliser light is not flashing as usual. So I stick in a spare battery and the car fires up and goes like a dream etc. Now today I go to start it up and........the battery is flat again but I have left no lights or radio on. I even turned off my alarm system to see if that would help. Any advice? I'm getting piddled off recharging and changing batteries!

Cheers,Charlie
www.charles.farquhar.btinternet.co.uk
 

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A couple thoughts Sgt.... Make sure your charging system is working, i.e. capable of putting out several amps over driving load at a couple of volts above battery voltage, or else you'll simply discharge while you are driving. A strong single wire alternator w/ a built-in regulator is a great investment for an old Mustang. A solid-state regulator is a must. Second, when parked, measure current drain with a current meter (volt meter across a shunt will work, Volts/Ohms=Amps. A small drain (milliamps) is normal for the clock, alarm, off-stereo, etc. Much more indicates a problem that could discharge you faster than a fortnight. One at a time disconnect components to find the bad actor draining power. You might ultimately find out your wiring harness is just shot.
 

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Try tightening the battery terminals. Sounds like a symptom of that (been there, done that!)

Gary
 

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While you are still looking for the problem, just unhook the battery. You can also get a battery shut-off switch (I found one in the Virginia Mustang catalog) which hooks to the terminal and your ground hooks to it. It has a threaded knob that you unscrew to disconnect the ground. It runs about $7.
 

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Get this diagnosed by an expert.....it could be a semi-shorted diode in the alternator, and when it shorts completely, it could fry your wiring
 
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