Battery Eater

Doing the same exact thing over and over and expecting different results is a sure sign of insanity. You alternator/regulator is fried. Most likely a blown diode. Replace the alternator. Charge the battery.

Reply to
bomar
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I have a '92 F-150 (5.0-lt, 8-cyl) that's chewing through batteries like they're appetizers. Currently, I've gone through three batteries in three weeks. I explained away the first draining as an old battery that I'd had for over a year with little activity (parked in my driveway for weeks at a time between mild uses.) I purchased a new battery and parked it for ten days. When I went to start up the truck, nothing turned over. I checked the radio, lights (head, glove, and cabin), and the battery connection. None were clicked on, or in the case of the glove compartment, compressed into the off position. The battery cable doesn't show any signs of wear or cuts. The latest battery didn't last a week before it started showing signs of being severely drained.

Other thoughts on where I might start checking for a system leak?

Many thanks.

The Ranger

Reply to
The Ranger

first, make sure it's being charged

have the alternator checked for a bad diode

Reply to
TranSurgeon

Well put, bomar. And remember, two-thirds of life's problems require a volt meter to solve. Get yourself one next time to go to town. In the future, your immediate reaction to a dead battery will be "Wonder if my alternator works? Well, I guess I better check...."

Reply to
Joe

That may not explain why his new battery was dead after leaving it parked unless it was dead when he parked it. He may have a current drain that he does not know about.

One thing I would do would be to turn the truck off, pull off a battery lead and test for current with the multimeter that everyone should have. Even a small (100mA) draw can run a new battery flat in a week.

Stephen

Joe wrote:

Reply to
Stephen

Before you do anything check the fuses. I had a competent mechanic tell me I needed an alternator and a battery on my 96 Ranger, so I replaced both. The problem didn't go away. A neighbor looked under the hood and suggested we start checking things from the fusebox out. We found a blown 50 cent fuse, which solved the problem. Oh well, at least I got some new parts, and for once didn't have to change them on the side of the road in the rain! James F. Hodgdon Jr. Hodgdon Scale Models

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Reply to
Hdgdn

On Sun, 18 Apr 2004 22:41:39 -0700, Stephen rearranged some electrons to form:

A shorted diode pair in the rectifier circuit will cause a battery drain. Replace or rebuild the alternator.

Reply to
David M

That can be true but there are any number of places where an unwanted current drain can occur that have nothing to do with the alternator. Replacing the alternator would be not fix the problem. I would start with the tests that I can do for free:

  1. Test for current drain with the ignition off.
  2. Test for charging current and voltage with the engine running.
  3. Discharge test on the battery.

I once had a dash clock that malfunctioned. It was flashing all the time but I didn't think it was a problem. I didn't start my van for a week and the battery was dead. I put the battery on the charger and then did test 1. The ammeter showed a current that was bouncing between

50 and 200 mA. That baffled me until I realized that it was varying at the same rate that my clock was flashing.

A lot of charging/starting problems are also caused by lousy ground straps. The battery may be charged, the lights, radio etc work but the vehicle will not start. The current required to start causes a large voltage drop across the high resistance of the lousy connection and the starter won't turn over.

In this case, the vehicle will jump start if you put the jumpers on the frame but not on the battery. The lesson is to always jump with the ground clipped to the frame.

If you skip steps in your diagnosis you may also skip past the solution.

Just my two cents...

Stephen

Reply to
Stephen

Reply to
coryrhonda

On Tue, 20 Apr 2004 00:21:17 +0000, Stephen rearranged some electrons to form:

One thing for sure, Ranger, another new battery is not going to fix the problem.

Given the fact that he has put 3 batteries in it in 3 weeks, I would not suspect the battery itself. Also, per the OP description, the truck ran for a week before it quit starting. This could point to the battery not being charged sufficiently.

Although it could be a bad ground, or a wacky current drain, I would still bet on the alternator as the most likely cause. You can take it off and take it to Autozone, and they will test it for you for free.

Reply to
David M

snip

Unless they're not "new".

snip

Reply to
Bill Vajk

A lot of places that sell batteries and alternators around here will test them in the vehicle for free. They want to know which one they can sell you. That should have been done the first or at least the second time the battery was replaced.

Stephen

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Reply to
Stephen

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