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98 Ford Ranger 2.5L starter/possible parasitic drawn on battery.


Doomgaze

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Greetings y'all

I'm having a issue with my truck having a low battery after parked over night. I've been having an issue with my starter and have ordered one to replace the old starter. Sometimes it works sometimes it doesn't. Would a bad starter/solenoid cause a parasitic drawn on the battery? Battery is brand new and alternator isn't very old but the truck had been sitting for about 2 years. No issues when I parked it back then. I plan on replacing the starter Friday and will update the post whether or not this fixed the issue. Just wanted to make this post to get any ideas on what to check for in case the starter is not the issue.

Thank y'all for your time.
 


franklin2

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I have never seen a solenoid or a starter cause a parasitic draw. They either work when commanded, or they don't. If the solenoid sticks, it will cause the starter to run all the time.

If you want to check to see if you have a draw, get a old simple testlight with the regular bulb in it, not a LED type. Take the negative battery cable off and lay it on a rag. Clip the testlight to the battery neg terminal, and stick the probe on the terminal on the rag. If the testlight lights up bright, you do have a drain.

Ford has some systems in their vehicles that have to go to sleep after a few minutes. If you have something like this, you will have to wait on those, and make sure the doors are closed and the domelights are off. Once you are sure your vehicle went to sleep, check the light(somehow leave it connected at all times). The computer and radio memories are not enough to light the testlight bright, but a drain will. You can then start pulling fuses to see if the light goes out. Once it goes out you have found the circuit causing the drain. You can also pull the wires off the alternator and see if the light goes out.
 

Doomgaze

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Good idea, I had put a dome light in before I last parked the truck but took it out the other day. It wasn't the right one for my model of Ranger but it worked. When the light was in though the dome light never came on. I never had a dome light since I had the truck. I did notice that my radio wasn't working anymore and put a new fuse in but the radio isn't working again. I'll get a tester light and do like you said and see if I can locate the issue. The starter has given me issues in the past so I just assumed it may be faulty. I'd assume the alternator is fine since the truck doesn't die when I'm driving it.
 

franklin2

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The alternator can have a bad diode in it. It will charge the battery (though not as good) but if one of the diodes is shorted, it will present a drain to the system when the alternator is not turning. There are 6 diodes in there.
 

2011Supercab

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Brand new battery?

New when you parked the truck 2 years ago, or new in the last few days?
 

Doomgaze

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The alternator can have a bad diode in it. It will charge the battery (though not as good) but if one of the diodes is shorted, it will present a drain to the system when the alternator is not turning. There are 6 diodes in there.
Yeah, that is something I'm definitely going to check. I can test an alternator with a multimeter instead of pulling it and taking it to a parts place correct?
 

franklin2

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Yeah, that is something I'm definitely going to check. I can test an alternator with a multimeter instead of pulling it and taking it to a parts place correct?
No, you need a oscilloscope to check it. Or you possibly could put your meter on A/C and see what reading you get, but I do not know what would be a good reading or a bad reading. An alternator generates 3 phase AC voltage, thus is why it's called a alternator. The diodes change this 3 phase A/C to single phase DC for the vehicle to use.

If you simply do the testlight test, and if the light is lit up, you can unplug the wiring and unbolt the large wire off the alternator. If the light goes out, then the alternator was the problem.
 

Doomgaze

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No, you need a oscilloscope to check it. Or you possibly could put your meter on A/C and see what reading you get, but I do not know what would be a good reading or a bad reading. An alternator generates 3 phase AC voltage, thus is why it's called a alternator. The diodes change this 3 phase A/C to single phase DC for the vehicle to use.

If you simply do the testlight test, and if the light is lit up, you can unplug the wiring and unbolt the large wire off the alternator. If the light goes out, then the alternator was the problem.
Update: No charging issue/parasitic drawn issue. Starter solenoid positive stud on old Motorcraft was loose and warn out. Not allowing the starter to work. Put a new starter in cranked up with no issues. Thanks, Franklin2 for the information.
 

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