No Charging
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Freshman User
Joined: Dec 2004
Posts: 43
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No Charging
The UVC harness came loose on the driver's side and I ended up running on only the passenger side for a bit until I could get back to the house and fix it. As soon as that was fixed, the battery light on the dash was lit constantly. The batteries are less than a week old, and the alternator tested just tested good today, however it is not charging when on the truck. There is 12 volts from the post on the alternator to ground when running. I've also ohmed from the post on the alternator to both battery positive terminals.
I'm thinking that I had to mess something up when I pulled the valve cover to plug in the UVC harness, but I"m not sure where to start...Any help is appreciated
I'm thinking that I had to mess something up when I pulled the valve cover to plug in the UVC harness, but I"m not sure where to start...Any help is appreciated
Post Fiend
Joined: Mar 2007
Posts: 26,966
Likes: 50
From: Texas
You should see more than 12v from the alternator when running. High 13's or low 14's is what you should be seeing. Try turning on the headlights, hazards, radio, & AC and see what your reading from the alternator is. If it doesn't go above 12 volts, you need a new one.
The auto stores don't always identify a bad alternator. I've had one that bench tested good (supposedly) but a new alternator fixed the low voltage issue.
The auto stores don't always identify a bad alternator. I've had one that bench tested good (supposedly) but a new alternator fixed the low voltage issue.
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Freshman User
Joined: Dec 2004
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Voltage goes down a bit to 11.75 with everything on and engine running. I may just have to bite the bullet on a new alternator and hope it fixes the problem. This one is a few years old.
What are the two green wires that plug into the alternator for?
What are the two green wires that plug into the alternator for?
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Freshman User
Joined: Dec 2004
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Fixed It! It was the alternator. I installed a new 200 amp unit from DB electric and their wire kit from the alternator to the battery. After the install, the battery light was off, but there was still no charging. After checking everything again, I checked all of the fuses again, and found a 5-amp that was blown in the engine compartment. Replaced that, and there was charging. The next day, one of the brand new wal-mart batteries began spewing acid everywhere. Replaced that, and now everything seems to be 100%. Ready for Winter!!
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Post Fiend
Joined: Nov 2007
Posts: 9,549
Likes: 14
From: Payson, AZ
Good fix and thanks for getting back to us. Can you tell us which fuse you replaced? Keep the old alt as a spare. It may be good and the blown fuse may have been the real problem.
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Postmaster
Joined: Jul 2004
Posts: 3,156
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From: Yuba City, CA.
Yes, thanks for getting back to us. Reps sent!
Posting Guru
Joined: Nov 2007
Posts: 1,521
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From: Tupelo,Ms
yea what fuse... mine started this about 2 hr ago. batt light was on its reading 12v at both batts and 11.6 when at idle and all lights on. batteries are like 5yr old and alternator is 10 ha ha im hoping it may be this fuse.... guess your problem moved to my truck ha ha
Post Fiend
Joined: Nov 2007
Posts: 9,549
Likes: 14
From: Payson, AZ
My guess is that it was a voltae regulator "A" field fuse. The fuse chart doesn't make a lot of sense but it could have been under hood fuse #5, 6 or 7. Check those.
Postmaster
Joined: Oct 2003
Posts: 4,516
Likes: 1
From: SoCal
When my 97 Explorer quit charging a quick look at the charge circuit wiring diagram told me which fuses to check.
BINGO, mini fuse 6 labeled "generator/voltage regulator" in the power dist box was blown. Replaced it & problem solved.
BINGO, mini fuse 6 labeled "generator/voltage regulator" in the power dist box was blown. Replaced it & problem solved.
Fleet Owner
Joined: Jun 2004
Posts: 25,090
Likes: 1,111
From: Rio Rico, AZ.
Fixed It! It was the alternator. I installed a new 200 amp unit from DB electric and their wire kit from the alternator to the battery. After the install, the battery light was off, but there was still no charging. After checking everything again, I checked all of the fuses again, and found a 5-amp that was blown in the engine compartment. Replaced that, and there was charging. The next day, one of the brand new wal-mart batteries began spewing acid everywhere. Replaced that, and now everything seems to be 100%. Ready for Winter!!
I recommend checking the voltage on that new alternator.