charging question ford f150

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1985 Ford F 150 302 EFI 200,000 miles. Recent history--- A few months ago it was supposed to get pretty cold and I knew I didn't have enough antifreeze in it
Also needed a new Battery. Topped it off and installed battery etc... well a couple months later I went to drive it and forgot I hadn't fastened the Battery down, turned a corner, everything died instantly. You guessed it, battery slid and shorted against the voltage regulator. Didn't know what it was at the time because I previously had other electrical problems.

any how long story but now it is overcharging. Replaced voltage reg. first, didn't solve, replaced alternator and still over charging. Batt..13v engine off,
idle 15.25-15.50v, turn on headlights and heater blower on high and pegs my tester past 16v

any thoughts guys
Thanks

posted by  thefonz

???? did you replace the regulator then the alt is it posible the old alt fried the new reg before new alt was installed maybe a fusable link blew not able to check my manuals now not at home for wiring

posted by  osborste

I'm going to take my old alt to parts store and let them bench test and see what it is putting out. I don't know if they can test the old regulator or not.
Maybe that will help us figure this mess out.

posted by  thefonz

found this at www.autozone.com hope it helps

posted by  osborste

OK went to the first parts store, what a joke! hooked it up and said bearings were shot, they are not... they are tight and no play whatsoever, he hooked it up wrong also, so I went across the street to auto zone, said alt was fine, then they bench tested regulator and said it was fine. so after new stuff it is still over charging. If is was a fuseable link would it still be charging at all? I am going to try and check some wires to the regulator. Maybe fried and didn't notice. Thanks for the help

just got back in. tested all fusable links i could see, all good.tested fuses in fuse panel under dash, all good. is it possible wrong voltage reg for the size alt??

also started truck and unhooked battery, hooked up tester to batt. leads and still pegged past 16v [this time at idle] no accessories on.

posted by  thefonz

ok looked around the web and yes the regulator needs to match the amps of the alternater its shows 40/60 amp and75/90 amp and 100amp alternater all the regs are diff #'s for each group

posted by  osborste

if ur voltage reg and alt checks out. then its ur battery or wiring from alt to battery.. check cable for voltage drop and reistance.

charging voltage will be high if bat is near dead. it requires more volts to recharge a bad battery. but more volts will kill ur computer so ...

posted by  thongsai

thanks for the help guys, battery is good, checked it with a load test also. I will check out tomorrow and see if alt and regulator are right for each other.
If wires had voltage drop wouldn't that make it undercharge instead of over charge? Also will a needle type tester be adaquate to test wire resistance?
Thanks again!

posted by  thefonz

I hardly ever drive this truck but worked on it this weekend and got er fixed!
I put a ground wire from alt. to frame and she's charging right on the money,
Thanks for the help :thumbs:

posted by  thefonz

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