# Charging problem with F250 1988



## hardworkingwoman (Jun 4, 2009)

Hi,

We are having a problem with our 1988 Ford F250 heavy duty pick up truck 460 gas V8. We replaced the alternator twice and the charging system is not charging. The battery shows up on the multitester is reading 12.12 volts when it is running. It should read 13.5 to 14 volts. Checked the fuesable links and there is nothing wrong with them. Does anyone know what this problem might be? We are stumped, and very frustrated.

thank you !!!!


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## agmantoo (May 23, 2003)

How clean are the battery cables where they affix to the battery posts? Clean the inside of the cable ends if you haven't already.


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## zant (Dec 1, 2005)

Voltage regulator?...Solenoid draining energy??


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## Danaus29 (Sep 12, 2005)

I would have the voltage regulator tested.


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## Bearfootfarm (Jul 13, 2006)

I agree with Agman.

The cables could also be corroded under the insulation where you can't see it.


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## InvalidID (Feb 18, 2011)

If the battery isn't showing a proper charge have you had it tested? A weak battery will kill alternators. Been there.

ETA: If you don't know how to test the battery Autozone and NAPA do this for free.


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## Malamute (Sep 15, 2011)

All good comments, but it's quite possible to get bad alternators. It may be worth having one bench tested, especially if it's a rebuilt, and the battery *load* tested. 

I think the voltage regulator should be solid state, internal to the alternator.

If all else shows good, you can have corrosion inside the battery cables that can inhibit current, as was mentioned. Also, side terminal cables have the plastic covers on the ends that eventually get cruddy under the plastic, and there's no way to properly clean them. I was having ongoing trouble with my Suburban, and finally cut the plastic end covers off, cleaned everything well, and it's been fine ever since.


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## Danaus29 (Sep 12, 2005)

I had an 85 Ford with a 302 that ate alternators and batteries. Turned out the voltage regulator was bad. Changed that out and had no more problems. Auto Zone and Advance Auto can check them. At any rate it's worth looking into.

If all else checks good, it's really not difficult to change the battery cables.

One last thought, did you get the proper alternator for your engine? I know for my van there were 2 different alternators listed. But the only one that really fit was the higher rated one. If you're trying to get by on the cheap you may have got the wrong one. Or the previous owner could have tried to get by on the cheap and put the wrong one in. That happens occasionally.


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## hardworkingwoman (Jun 4, 2009)

Well the battery is new and we had to take it to the shop. With all of my husbands knowledge on vehicles this has just stumped him. So when they figure it out I will let you know what the problem is! We do not use cheap items on the vehicles because they are not worth it. He will go to lengths to get factory parts for them and if he can't get that he goes to the next best thing. The ford dealer said that he can not even get this particular alternator anymore. Sooooo? We will see. Thanks for all of your answers be back when we find out.


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## glenn amolenaar (Mar 3, 2007)

I'm waiting your results I have an 86 F250 same problem it is a farm truck so I cant take it to town. Replaced and done what the parts store said still no luck. 
Glenn


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## Esteban29304 (Apr 29, 2003)

I have seen so many bad " rebuilt " alternators in my lifetime. Nothing more than minor patchwork was done to them, & then re-painted. I have gotten 3 from a discount parts supplier before getting a good one. I have seen junk rebuilds from Napa & Car Quest as well. I suggest to find a GOOD shop to rebuild alternators & starters . 
Battery on the Ford 460 needs to be big & strong. All cables in great condition. Locate grounding cable & check it , too. Even add another if in doubt. If you get it running & charging fine, you may want to do a " starter draw" test. A starter going bad can drain a battery in a hurry. Also, check to see if there isn't something drwaing power from the battery when parked, overnight.


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## foxtrapper (Dec 23, 2003)

Bench test the alternator. As mentioned by another, they don't always work out of the box, especially rebuilt units. Bench test both by spinning, and by checking the components. Many a bad alternator with a bad diode will produce enough charge to false pass a spin test. Your clue on installation is a faint charge effect under certain conditions.

The regulator and rectifier are integral to the alternator assembly on your vehicle. When you replace the "alternator" you're replacing all of this.

If it's been determined that the alternator is indeed good and capable of charging, the only reason it will not is because of lack of electrical connection to complete the circuit. Somewhere in the path you have an open. Most commonly a broken connector, a disconnected connector, dirty connection. Rarer is the broken wire or blown fuseable link. With a meter, check the continuity of the complete circuit, not just the hot leg.


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## hardworkingwoman (Jun 4, 2009)

If we only had a schematic diagram for this "specific truck". In the Chilton's book we have, it does not give this. Does anyone know where we can find this?


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## hardworkingwoman (Jun 4, 2009)

We have looked this up on google and it does not come up as what we need


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## Allen W (Aug 2, 2008)

This is the alternator that comes with leads attached that you have to patch into your old wiring harness? Don't have any answers but have had to replace a battery and alternator for the second time before every thing worked right.


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