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1987 - 1996 F150 & Larger F-Series Trucks 1987 - 1996 Ford F-150, F-250, F-350 and larger pickups - including the 1997 heavy-duty F250/F350+ trucks

Battery / Drain issue

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Old Aug 6, 2021 | 02:46 PM
  #16  
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Old Aug 6, 2021 | 03:06 PM
  #17  
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Thank you very much for diagram. I tried and failed looking for one. I believe I found it. I'm thing the small line to the left under the horse shoe looking line. Question. Do I just disconnect that one line and hook everything back up with battery? Sorry for such dumb questions but I just want to do this right. You see the line to the right behind the black boot looking.





 

Last edited by Sirriggs; Aug 6, 2021 at 03:09 PM.
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Old Aug 8, 2021 | 01:47 PM
  #18  
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Well finally caught the older guy at Advance and we ran some test and he said it was the alternator diao was bad so replaced it there with a new alternator. We talked a few minutes before hand and he felt that it was bad due to the fact it sat all day and the alternator was real hot to the touch even though the truck wasn't ran at all. I'm going to give it about 6 hrs sitting and double check to see if it cold. Before I went. I did the same thing and after checking it and it being hot, I went to my Dodge and did the same thing and it was cold so I'm sure I found the problem and solved it. It is charging a lot better in volts then before.
 
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Old Aug 9, 2021 | 07:22 AM
  #19  
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Glad to see you found a counter jockey who knows something about vehicles. I still find it unacceptable they cannot test an alternator for excessive AC ripple, bad diodes, using their alternator tester.
 
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Old Aug 9, 2021 | 10:35 AM
  #20  
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Originally Posted by rla2005
Glad to see you found a counter jockey who knows something about vehicles. I still find it unacceptable they cannot test an alternator for excessive AC ripple, bad diodes, using their alternator tester.
I don't know about all the various parts stores and models of testers out there, but I know that some of them that we had at the stores I worked in, checked for bad diodes and AC ripple.

But it's a crapshoot.
 
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Old Aug 9, 2021 | 03:35 PM
  #21  
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Originally Posted by SFaulken
I don't know about all the various parts stores and models of testers out there, but I know that some of them that we had at the stores I worked in, checked for bad diodes and AC ripple.

But it's a crapshoot.
I checked it a couple of times and voltage was good. The new alternator is nice and cool to the touch when not in use where the other was hot to touch when it was sitting. I guess it comes to who you talk to in these places? lol. I think my problem is solved. Thanks guys
 
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Old Aug 9, 2021 | 03:38 PM
  #22  
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Originally Posted by rla2005
Glad to see you found a counter jockey who knows something about vehicles. I still find it unacceptable they cannot test an alternator for excessive AC ripple, bad diodes, using their alternator tester.
Me too. Wiring has never been my strong suite. I can change most of anything but wiring throws me for a loop.
 
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Old Aug 9, 2021 | 04:48 PM
  #23  
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Sincerely glad to see you got this resolved. All the symptoms pointed to a bad alternator diode(s). In theory DVM set to AC volts range should have confirmed, but I refrain from suggesting to try that since I have not personally done it.

Happy trails!
 
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Old Aug 9, 2021 | 06:56 PM
  #24  
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Originally Posted by rla2005
Sincerely glad to see you got this resolved. All the symptoms pointed to a bad alternator diode(s). In theory DVM set to AC volts range should have confirmed, but I refrain from suggesting to try that since I have not personally done it.

Happy trails!
I also had in it the back on head that the alternator was done but I never had one that still seemed to be charging but the heat issue puzzled me. That's a new one for me. Either they worked or they didn't. I had a old 76 step side ( I wished I still had it) that would just never would work right in terms of electrical . Either the alt would go out or the solenoid on the fender. never both. The old guy down the road from me ( I was 18 then so now I'm that old guy.lol) did all kinds of checking and he could never find the culprit. It was so bad that I kept one of each behind the seat at all times because you never knew when or what would die. lol. It was the 1976 shirt step bed with round finders and chains on the tail gate. I kicked myself in the butt for letting it go. Just always liked that body style. The 74 long step was ok but sold it when I moved.

 
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Old Aug 10, 2021 | 04:29 AM
  #25  
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sorry i missed this until now. i could have saved you a lot of headaches.
first test i do for battery drain overnight is feel the alternator in the morning. if it is warm or hot, it is a bad diode.
 
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Old Aug 10, 2021 | 06:38 AM
  #26  
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My 1991 battery would be dead in 2-3 days of sitting. It ended up being a bad diode in the alternator. Replaced the alternator and I can let the truck sit for weeks and always start.
 
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Old Aug 10, 2021 | 02:21 PM
  #27  
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Well it doesn't help when the person that's having the issue isn't good or knowledgeable on doing electric troubleshooting. I never have had this type of problem with one before. It's either charging or not and often found when battery is dead and a simple test to see if it's charging or not. I'm starting new employment today so it was fixed in time but I may down the road invest in maybe a bigger load one since 95amps from what I read is on the low side which to me would make it work harder. When I turn on ac the gauge drops about a 1/8 or more. Where nothing else barely moves the needle. I just recharged the ac about two months ago so it's good.

My wife passed in April of this year and a sunk a decent amount of money on her 99 Dodge working on getting it road ready for our daughter down the road. It sat for around 5 yrs due to taking care of my wife so from valves to new upgrade intake and gaskets we're done. snapped the last bolt on it so I have to go back and take it off and remove that replace all the bolts but it runs smooth. So not only being busy but ate through my nest egg quickly. lol. So my plate has been full and my mind is burnt at times.

Thank you guys for all your help. It means a lot.
 
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Old Aug 11, 2021 | 01:25 PM
  #28  
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When I bought my 90 F150, the used car dealer told me the previous owner was a "mechanic" because he had installed a batter disconnect under the passenger wheel well. Well, I didn't turn off that disconnect and soon found out he had installed the $40 switch to keep the battery from dying. A little research and I found the fuel pump relay was sticking on and the FP was running continuously killing the battery. So I replaced the $12 FP relay to fix the problem the previous owner spent $40 on because he didn't know how to trouble shoot.

Have a friend with a battery drain problem on a Honda something. Dealer couldn't figure it out. He finally figured out the AC relay was sticking leaving the AC compressor clutch engaged which was draining his battery. He went back to dealer to explain the problem and fix and they insisted that couldn't happen. I wouldn't go back to that dealer myself...

I had never encountered the diode in the Alternator causing a battery drain issue. That is good info, and something to check if/when I ever experience battery drain issues in the future.

Broncobasher
 
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Old Aug 12, 2021 | 02:11 AM
  #29  
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Originally Posted by broncobasher
When I bought my 90 F150, the used car dealer told me the previous owner was a "mechanic" because he had installed a batter disconnect under the passenger wheel well. Well, I didn't turn off that disconnect and soon found out he had installed the $40 switch to keep the battery from dying. A little research and I found the fuel pump relay was sticking on and the FP was running continuously killing the battery. So I replaced the $12 FP relay to fix the problem the previous owner spent $40 on because he didn't know how to trouble shoot.

Have a friend with a battery drain problem on a Honda something. Dealer couldn't figure it out. He finally figured out the AC relay was sticking leaving the AC compressor clutch engaged which was draining his battery. He went back to dealer to explain the problem and fix and they insisted that couldn't happen. I wouldn't go back to that dealer myself...

I had never encountered the diode in the Alternator causing a battery drain issue. That is good info, and something to check if/when I ever experience battery drain issues in the future.

Broncobasher
This was the first for me as well. I check it while running and it was charging so I thought maybe something else. I learned a lot here myself.
 
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Old Aug 12, 2021 | 05:47 AM
  #30  
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Originally Posted by Sirriggs
This was the first for me as well. I check it while running and it was charging so I thought maybe something else. I learned a lot here myself.

I checked the fuses for parasitic draw using a youtube video I saw. Everything checked out to be good. My alternator was charging the battery with the right volts, but my battery would be dead in 2-3 days. I bought a new battery, still went dead in 2-3 days. I read on another Ford F150 Forum about a bad diode in the alternator can drain the battery. I bought a new rebuilt alternator from my local auto parts store and it fixed my battery drain. That was 5 or 6 years ago and still working. My truck will sit for 1-2 weeks and starts every time. I've only put 5,000 miles on it in 10 years
 
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