Last friday night my lights started dimming while driving, saturday i checked the charging output nothing and when i took the positive cable off it died, so i replaced the voltage reg. and alternator, that took care of the charging problem? Sunday morning i go to start it and nothing battery completely dead, charged battery and drove seemed to be fine just thought maybe i drained the battery when it was not charging. Go out this morning and nothing battery dead as can be, seems like something is draining it over nite, could something in the new alt. or reg. be doing it? Battery is only 2 months old when i charge it and load test it tests out OK any suggestions on where or what to check on. 84 f150 351W.
Many Thanks!
Carl

 

My .02 When you disconnect the positive cable on an alternator system to "test it," you blow one or more diodes in the alternator anyways. Another common detructive practice is to take the new alternator out of the box and spin it by hand. This can also blow a diode or two. This info won't solve the original problem, but it will save you a future head-ache. I'd suggest you attach a load meter to your battery with the engine running and see if you're putting out 13-14 volts. If less, you,ve probrably blown a diode.

 

check to see if there are any burned wires by the light switch, my 84 f-250 had the parking light wire from the switch to the tail lights insulation melt and discharge the batt a couple times.

 

[updated:LAST EDITED ON 15-Apr-02 AT 05:14 PM (EST)]Once you get your charging system checked out take a second look at your battery. Not all batteries are equal. Make sure your battery is rated for your vehicle. Also even a two month old battery can go bad, especially if it's a cheap one and you discharged it deeply, then fried it back into service with a quick charge. That's hard on a battery.

Cheap batteries can also ruin your charging system. If they don't have enough amps they will ruin your starter and solinoid too. If you come to idle with your lights on and your lights dim, very likely your battery is toast. (assuming the charging system is ok)

I recommend that you use a hot battery like an Interstate Battery. Avoid discount batteries from the local jobber or auto parts store. Beware of ratings stamped on cheap batteries, they fib a bit here and there. Unless of course you want to cheap out on the battery, then you'll have fun replacing alternators, starters and other stuff that goes bad when the battery is not pulling it's load.

BigBlue2

 

Well, i've charged the battery back up and she started fine,hooked up a tester between the neg. battery cable and neg. battery post,my needle on the tester then drops/moves below zero, does this mean i have a short? The output while running is around 17 volts, is this a good number? going to let it sit for a day and see what happens, thanks guys, Carl

 

>Well, i've charged the battery back up and she started
>fine,hooked up a tester between the neg. battery cable and
>neg. battery post,my needle on the tester then drops/moves
>below zero, does this mean i have a short?

Probably means your ammeter was hooked up backwards. Try reversing the leads.

> The output while
>running is around 17 volts, is this a good number?

I don't think so. The voltage regulator should keep it under 15V.
What happens when you turn the headlights on?

If you don't mind Carl. Could you tell me where the wire from the Stator connection on the alternator goes? (see 84 F150 Overcharging)

Thanks,
Tim

 

https://www.ford-trucks.com/user_gallery/sizeimage.php?&photoid=1730&.jpg

[b][i][font color=red]Dennis[/font][i][b]

[font color=red]Calgary,Alberta,Canada[/font]
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[font color=red]If New Ford Parts Is What You're Cravin',
Then Buy Them HERE,At Motorhaven!

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[font color =red] Please Don't Ask Me Any Tough Questions,
"I'm Saving My Memory For When I Develop Alzheimer's" [/font]


[font color=blue]78 F-150 429CJ,Silver,Explorer Pkg.
641/2-Mustang 260,Pre-World's Fair Car.
64-Fairlane500 S/C waiting for a 390-4spd.
68-Mustang 289-Sunlit Gold 80,892Mi
78-Buick LeSabre 403 4V
84 Volvo DL Wagon [/font]

 

Sounds like a blown diode in the Altenator. That would allow the alt to put out higher voltage and would put a reverse drain on your battery when the engine was off.

 

I'm confussed, one post saying low voltage output indicates bad diode another saying high voltage indicates bad diode? Anyway, took the alt. off and had it tested today checked out OK. My battery is still getting drained over nite somehow, i mean it has nothing left at all not even a spark, seems to come back up when on the charger overnite thou. Is there anyway i can unhook any wires on the alt. to eliminate it for sure that would lead me to a problem/short somewhere else, or does everything go through it, what about unplugging the voltage reg. ( I'm talking doing this while it is sitting over nite ). What's up with the stator wire going to the choke? Can the choke be giving me problems in the charging system? Thanks for alll your help/advice guys, glad i found this site, way my truck has been acting lately going to have to make it my home page.(lol) Thanks, again!
-Carl

 

17 volts is way too high. Did you load test the battery with it out of the car? It may be fried already.

 

[updated:LAST EDITED ON 17-Apr-02 AT 11:36 PM (EST)]>I'm confussed, one post saying low voltage output indicates
>bad diode another saying high voltage indicates bad diode?
>Anyway, took the alt. off and had it tested today checked
>out OK. My battery is still getting drained over nite
>somehow, i mean it has nothing left at all not even a spark,
>seems to come back up when on the charger overnite thou. Is
>there anyway i can unhook any wires on the alt. to eliminate
>it for sure that would lead me to a problem/short somewhere
>else, or does everything go through it, what about
>unplugging the voltage reg. ( I'm talking doing this while
>it is sitting over nite ). What's up with the stator wire
>going to the choke? Can the choke be giving me problems in
>the charging system? Thanks for alll your help/advice guys,
>glad i found this site, way my truck has been acting lately
>going to have to make it my home page.(lol) Thanks, again!
>-Carl



Here is one of the links that I have with My gallery
Have a good read on me!


http://www.inliners.org/tech/tech6.html


[b][i][font color=red]Dennis[/font][i][b]

[font color=red]Calgary,Alberta,Canada[/font]
http://www.clubfte.com/users/mil1ion/Minimorleytruck.JPG

http://www.clubfte.com/users/mil1ion/FordTruckCodes.html

[font color=red]If New Ford Parts Is What You're Cravin',
Then Buy Them HERE,At Motorhaven!

[/font]


http://www.clubfte.com/users/mil1ion/Mil1ion.html

[font color =red] Please Don't Ask Me Any Tough Questions,
"I'm Saving My Memory For When I Develop Alzheimer's" [/font]


[font color=blue]78 F-150 429CJ,Silver,Explorer Pkg.
641/2-Mustang 260,Pre-World's Fair Car.
64-Fairlane500 S/C waiting for a 390-4spd.
68-Mustang 289-Sunlit Gold 80,892Mi
78-Buick LeSabre 403 4V
84 Volvo DL Wagon [/font]

 

Dennis,

Great sight!!!! It's definately in my bookmarks now.

 

Thanks! Dennis, cant make it any more simple than that.
~Carl

 

Here's my test results, when i hook a test light up
between my neg. cable and neg. battery post it does
light up(really bright), pulled all the fuses one
by one still stayed lit, pulled field wire off alt.
it goes out. Look's like my alt. is the one giving
me the problem, everyone agree? It also is putting
out close to 18 volts when running, to high correct?
Either i got a bad one off the shelf or i damaged it doing
the ole take the cable off to see if it still runs trick!
When bench/load tested it checked out OK.
Thanks
Carl

 

Replaced the alt. same problem, took reg. to get tested
it failed replaced reg. Problem solved, thanks guys!

Just a note my wiring is not as shown in the diagram, Battery wire goes to solenoid - Field wire goes to the F connection on reg. -
Stator wire goes to S connection on reg. (not to my choke as shown)
choke wire goes into a harness below engine did not follow to see where it ended up.
Thanks again!
-Carl