Battery light on, voltage gauge Normal ~14v at batteries?

[milner351]

The voltage gauge is in the normal range, and with an old analog volt meter I measure about 14 volts at idle on both batteries (tough to tell exactly on a 50v scale).

I wiggled the plug on top the alternator where I've had issues in the past - no effect.

Any ideas?

 

[yoslick]

Try disconnecting both your pos cables while its running, if it dies your alternator has problems, run it into a NAPA and they'll test it free....

Slick!

 

[Double-S-Diesel]

do not disconnect batteries while running you run the risk of damaging the cpu and other electrical things

 

[geonc]

do not disconnect batteries while running you run the risk of damaging the cpu and other electrical things

Shoulda put that in bold!........never mind did anywayz!

Milner, does your radio howl, or headlights dim at idle? I'm thinking bad diode.....just find an Advance or Auto Zone---they test for free!

btw....have you done any work to the passenger side of the eng recently?....there is a small single pin plug that sits on top of the alt that allways seems to get smashed when working on the truck........

 

[94f450sd]

check the little plug like geo mentioned.if that doesnt do it replace the big plug.advance and autozone sells them in the wireing section.ford has always had issues with the alternator connectors since going to internal regulators.i replaced the alterntor on my 95 5 times before replaceing the big plug for this reason.

Try disconnecting both your pos cables while its running,

first thing you NEVER disconnect the positive cables with it running or not.ALWAYS disconnect the negatives first!!!!! good way to fry an ecm.have you ever had a battery explode from doing this?i have.crown vic ex police car charging at a full 100 amps made a big boom and thought for sure i lost my hand.

 

[milner351]

Thanks guys - I'll look at those plugs and see if I can get a replacement - I have patched the green wire on the three wire plug once before - getting a new one is a good idea for sure.

Hopefully the danged thing will start like it should this morning and I can get it over to the shop where I can work on it inside!

 

[geonc]

Thanks guys - I'll look at those plugs and see if I can get a replacement - I have patched the green wire on the three wire plug once before - getting a new one is a good idea for sure.

Wouldn't have been cause a broke belt ripped them up ?

had that happen to mine when the tensioner went Tango Uniform and threw the belt and ripped the wires....

 

[milner351]

Well - there's good news and bad.

I'll get the bad out of the way first - I couldn't find a pigtail harness anywhere... so, I had to repair what I had.

Turns out the green / red wire had a bare spot and had continuity, but I figured it would be best to splice and shrink wrap in a new piece of wire.

I also cleaned the terminal in the alternator where the single pin connector plugs in - it had some green funk on it.

After those operations - no more battery light.

Thanks a lot for your help guys, truly appreciate it.

Now if I can just get this '99 running right for a friend of mine - I'll be able to get back to my winter projects!