Alright guys im stumped. Battery light came on about two months ago it would flicker. So i had Auto zone check it out batteries were good just needed a charge. so i charged them no fix so i said alright ill do the Alternator did that and then beginning of this week it happened again so checked it went back got a replacement alternator since they said it tested bad. Put the new one on and didnt change anything. Check my batteries they were reading 10v each. I charged them and they wouldn't hold a charge. so i replacement both batteries.

So i have a new alternator and two new batteries light is still on.

Contacted my tech (whose a friend) he said to check the wiring going to the alt he said both wires should read 12v on constant other when the key is turned on. Tested the constant it has 12v other reads 6-8v with key on.

He also said sometimes the wiring on the X pipe can short the alternator? i unhooked all the wiring from the Xpipe nothing changed per battery light being on or off.

So what should i do.?

also my dash lights dont work but thats been like that for awhile (bulbs are all good)

Forgot to mention sometimes the light goes off but seems to stay on 90% of the time.

 

By any chance your truck is equiped with dual alternator? I had a problem like this to at work replaced everything like you with no luck untill I replaced the bottom alt, problem got fixed. You might also want to check your grounds

 

Wheres the bottom one at? never heard of two alts from the factory and any chance theres a graph that shows all the grounds relating to batteries / charging system?

 

Passenger side on the bottom

 

I checked didnt see one my graph also dosnt show a solid line for how the belt runs it notices that if there were a second alt it would run that way but its a dotted line not solid

 

Did you visually check if you had an alt? If you dont have one check all your grounds, most likely the problem.

 

yeah i got under and checked. guess ill have to trace all the grounds unless we can find a graph to make it easier lol

 

Sorry, phone cant post graphs or anything else

 

alright looks like the grounds for the batteries just mount to the block.

 

They also go to the chassi check those as well.

 

Well still having issues!

While running if i unplug the wires that go to the alternator the battery light goes off.

Currently either plugged in or not i get no charge from the alternator it idled in my drive way for 2 minutes batteries went from 11-8v with just lights on

tech said charge the batteries and drive it since hes checking it out tomorrow.

Anyone have any ideas? that i can check tonight

 

Here is some reading for you TJ. Might or might not lead you to your problem.

https://www.ford-trucks.com/forums/1...tor-eater.html

https://www.ford-trucks.com/forums/1...ternators.html

 

Well it started strong this morning and I let it sit for 10minutes on high idle. Checked my batteries and I'm getting 14.4v. But light stays on I did read that sometimes the reman alternators from advanced have that issue. My tech is checking it out tonight he said it maybe the alternator side for that plug. I did notice that the wiring on the x pipe was lose so that very well maybe why it wasn't charging but I'll hopefully have a finally verdict tonight

 

For an update truck is running good now. had my tech look at it and the only thing he could try and think was the issue is the wire that goes from the alternator to the dash light. long story short i ended up getting a brand new alternator (duralast gold) and since then its been great charges 15v. Previous alternators were re-man ones from autozone clearly will not do that again. thanks for the help guys!