over charging issue

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Nov 14, 2015 | 09:43 PM

86dieselnut

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over charging issue

I have an 86 250 with the 6.9 diesel. I have been having issues with over charging at idle i have 13.5v and reved up its putting out 16.5v i have replaced the regular multiple times with no change and i have noticed that it gets very hot as well. I unplug the regulator and voltage drop to battery voltage. On the regulator terminals the f is connected to the alternator with a orange wire the s is a green and red wire with ign power the a is a yellow wire with battery voltage. Im not sure if I have a short anywhere and i can't find the right wiring diagram anywhere any help is appreciated. .. thanks

Nov 15, 2015 | 04:13 AM

ArdWrknTrk

pedant

Joined: Jan 2008

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From: EXTREME southwest CT

Do you have an ammeter or just a charge light?
If there is battery voltage present at the yellow (sense) wire this is correct.
You may just have to add a ground to the mounting bolt of the regulator case.
This has resolved a full field charge problem for others before.

Nov 15, 2015 | 06:38 AM

Franklin2

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From: Virginia

How are you checking the voltage and where? If you are using a handheld meter, what voltage reading do you get on the battery with the engine off?

Nov 15, 2015 | 08:54 AM

JimsRebel

Cargo Master

Joined: Mar 2008

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From: Washington

Is this a G2 ALT?

Nov 15, 2015 | 09:13 AM

ArdWrknTrk

pedant

Joined: Jan 2008

Posts: 23,576

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From: EXTREME southwest CT

Not if it has a regulator on the fender and a stud mounted charge cable.... as was already said.

Nov 15, 2015 | 12:20 PM

86dieselnut

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The truck only has an ammeter
And im checking with a mulitmeter at the right battery and the regulator connector. Engine off voltage is 13v

Nov 15, 2015 | 12:33 PM

ArdWrknTrk

pedant

Joined: Jan 2008

Posts: 23,576

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From: EXTREME southwest CT

Thats too high at rest.
You're going to boil your battery.

Add a ground wire to the regulator case and see if the voltage while running returns to normal. 14.7v max