Mechanics

FORD RANGER BATTERY PROBLEM

2002 Ford Ranger • 134,000 miles

Three times in the last 4 months when leaving work at the end of the day my battery (?) Is dead. I get a jump start, go to O'Rileys to have diagnosis done and no problems are found. Battery is fine. I replaced the 02 sensor about a year ago. No lights etc, left on.
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DHReynolds
April 10, 2013.



You likely have a parasitic draw somewhere in the car that has to be found.

There is a procedure for finding a battery draw like that.

You will need a digital ammeter and a jumper wire with clips on the ends to do this.
First rig any door switches so you can have a door open without triggering the interior lights and unplug the hood light. Remove one battery cable and attach the meter in series between the battery cable and battery post. Take the jumper wire and also attach it the same way. Leave the jumper wire on for at least 10 minutes to expire all the automatic timers. Now remove the jumper wire and read the meter. Anything over 50ma is too much draw. The way you locate this is to start removing fuses one at a time until the meter drops to normal level. This will be the circuit with something staying on. Determine what components are part of that circuit and check them individually until the problem is isolated.

This is only going to work if the issue is present at the time of testing and not an intermittent problem.

Wrenchtech
Apr 10, 2013.