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Discussion Starter · #1 ·
Well, now the latest problem I'm having is that something is draining the battery overnight and by morning's the battery is dead. I just changed batteries too- traded the red top for a Yellow top dual purpose deep discharge/starting. There's nothing being left on (that I know of. A lot of bulbs are missing but headlights aren't on and there's no radio) and some people have been saying that something could be grounding somewhere and causing the battery to drain.

Gonna have it in the shop monday or tuesday (slow charging the battery right now, and probably gonna leave it unhooked til I need to go somewhere with it) but I was wondering if anyone ever had the same problem.

Electrical stuff I've replaced already- solenoid's new, battery post cables are new, new Optima Yellow top battery, starter was new already and checks out fine. I've noticed that when a fully charged battery is being started for the first time, it'll fire right up after 1 short crank. Then after that it'll take a few cranks to fire.
 

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Rest in Peace Friend...
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Disconnect the negative lead. Hook up a 12V lamp or meter between the lead and the batttery post. If the light glows it indicates a drain. Remove one wire at a time from the battery side of the start solinoid. When the light goes out, you have found the failing circuit. Trace that wire and check places that it comes in contact with metal for possible insulation rub thru.

If the color of the wire is Yellow, it feeds things that are primarily hot when the key is on, (not all things feed by a yellow wire are under ignition key control). If it is Black with orange stripe, it feeds things that are hot all the time like curtesy lamps, main light switch, power locks, horn, speed control.

You can also start removing fuses one at a time to see what circuit is causing the drain.

A common problem for battery drain overnight is a curtesy lamp that is on but you don't notice it like in the glove compartment.

Keep in mind this is a quick list but hopefully gives you a place to start.

Good luck,
 

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I've been chasing mine for weeks....finally broke down to get a multimeter to see just what amount of juice was flowing and I am getting 11 volts with ignition off!!!

I bought a quick release for the negative cable in the mean time and disconnect every night until i figure this out.
 

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Had same problem with 89 full size

I just got mine back from the shop after having a drain also----after many hour of searching found out the regulator on the alternator for some reason was dragging 4 amps?? replaced alt and all is fine--had a friend with same problem and is was a short in the turn signal switch.
 

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pjmorgan22 said:
....finally broke down to get a multimeter to see just what amount of juice was flowing and I am getting 11 volts with ignition off!!!

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Voltage is "electrical pressure", you should have actually gotten 12 volts. The measurement for how much "juice is flowing" would be in amps.

Think of it like water from a pressure washer.

Voltage = PSI
Amps=gallons per minute
watts= how many square feet of sidewalk you could effectively wash with your maching.
 
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Discussion Starter · #6 ·
I used a little test light on the terminals and it lit up. I'm not sure if it's the right one to use (it says 6-24v on the side) but it glowed at any contact with the negative terminal and cable.

Gonna take it into the shop pretty soon. The guys there are really good at old 4x4s and have worked on the Bronco before. Gonna see if they can fix my fuel gauge and install a tach.
 

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Why take it to a shop? You are on the right track. Another guy is having the same trouble as you the first part of this you have alread ydone:

Buy a 6 dollar test light. Then disconnect the negative battery terminal and connect the test light between the negative post and the terminal. If the test light lights up brightly you have a power drain. Then pull the fuses for the interior lights until the test light is either dim or barely registering a draw. The test light will not go completely out because the computer will always draw a little bit of power in order to keep your radio presets and clock functioning among possible other things.

Let us know what fuse you pulled and then maybe we can help you out.
 
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Discussion Starter · #8 ·
Shop managed to find the prob. The alternator was draining it. They are also fixing some other crap on it, putting on the shocks and steering stabilizer, and attempting to fix the speedo and fuel gauges.

The shop comes pretty highly recommended and they don't charge very much for labor. It's case-by-case but usually they only charge for what the parts cost and not much for labor. They are a primarily commercial repair shop but my grandfather works for one of those companies that deal with the shop exclusively for their fleet problems, so they're sort of doing it as a favor.

I don't have a radio in it yet and the clock is kind of screwed up, won't adjust.
 

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Seeking Tanelorn
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Nevermind, I started a new thread over here.
 
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