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Old 05-23-2009, 06:37 PM
joedell joedell is offline
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Posts: 1
Default Charging system problem

2004 4.0 4X4 new battery slowing dying

new batt. fully charged (1275 on hydrometer) 1 month later, (1250)
disconnected batt. charged for 2 hrs. (1250) this is the 3rd battery in 8 months. each batteries life slowly shortened.

checked for ground with batt. disconnected. ohm meter reads ground in milli ohms and you can watch the resistance click down to zero. wait a minute, do it again and the same thing happens. pulled the 3 wire plug from the alternator and the ground cleared.

Read the ohms off the plug wires, g/r wire .720 milli ohms, bk/w and y wires read zero ohms.

Readings off the alternator socket reads g/r 1.49 k-ohms, bk/w 1.00-k ohms and the y 50-k ohms
Where do I go from here??????????
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Old 05-28-2009, 04:30 AM
sho_or_go sho_or_go is offline
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Join Date: May 2009
Posts: 59

buy a chevy, that way you know whats wrong with it every time. XD
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Old 06-17-2009, 11:43 PM
raven_17 raven_17 is offline
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Posts: 7

if the battery light is not on preform a paracitic draw test to rule out the car draining the battery while it sits such as overnight
2000 ford ranger xlt
4.0 v6
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Old 06-19-2009, 07:20 AM
mattmansrus mattmansrus is offline
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Posts: 3

The tests you will want to perform are as follows.
Put your multimeter on the leads of your battery and note the voltage with the engine off. crank the engine and note the lowest voltage your battery drops to (a Min/Max feature on the meter helps) and finally watch voltage the battery gets while the engine is running.

with the engine off your new battery should sit at 12.8, while cranking it shouldn't drop below 10 or 11 volts... if you see a bigger drop you have a weak battery... and while charging on your truck it should be in the 14v range, no lower than 13.8v. If lower than that you have an alternator problem.

finally put your meter on amps, disconnect your negative battery lead, make sure you switch the probes on the meter and put the multimeter inline between the ground post and the negative battery lead. note the current draw with the truck off and all doors closed. come back half hour later and see if its changed. your idle draw should be around two miliamps no more than about a half amp. if its more than that pull your fuses one by one till you see it drop, and that is the source of your current draw. good luck
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