[5literJeff]

Hey all, hopefully someone knows the answer to this.

My 86 5.0 recently started having a problem charging the battery.

I thought it was the battery because it was 3 years old so I replaced it to no avail. Next I took off the alternator and had it checked and it was fine. I took off the voltage regulator and noticed the terminals were fairly corroded so I replaced that as well as its connectors but it still was not charging the battery.

While I was checking the wires off the alternator I noticed that the connector directly off the alternator only had 2 prongs instead of three. See http://www.imagedump.com/index.cgi?pick=get&tp=439309 for the picture of the connector. Also http://www.imagedump.com/index.cgi?pick=get&tp=439316 for a smaller picture. I outlined in red where the missing metal prong is in both pictures.

My question is this ford factory as the connector is supposed to be or is it broken?

I was suspecting bad wires as the culprit for the charging problem but if that connector is broken that would prolly be the cause.

Also the connector it plugs into off the alternator is this one: http://www.imagedump.com/index.cgi?pick=get&tp=439318

Thanks in advance for any help!

[5literJeff]

Anyone?

[OTreborO]

I can't open the picture, work blocked your site

sorry

[5literJeff]

Ok as you can see by the below picture the red circle shows where there appears to be a metal prong missing. Or is that how its supposed to be?



Or

http://imageload.org/out.php/i17024_...cture00300.jpg

And the connector it plugs into is a three prong one as well (this comes directly off the back of the alternator and plugs into the wire harness):

[stang fanatic]

corroded connector can create the charging problem. if there is a wire on each end of where there is supposed to be a connector, and ones is missing, then its probaly corroded and broke off.

[OTreborO]

I would guess the overspray of blue paint killed it


Seriously, I think that you did loose a terminal, especially since you are having the charging issue.

I was hoping someone else would have the same year stang, and could confirm this for us? I have a 89/90, but it appears to be different. I will double check tonight. I have one connector that plugs into the side of the Alt, and one that plugs into the back. Does your Alt have wires that are attached by bolts??? Or does it also have the 2 plugs, I maybe not seeing the picture correctly................

Anyone? Bueler? Bueler? Farris Bueler?

[dcraig8]

if you have three wires going into the other side of the connector, then yes, its broken. if only two wires, then its fine. if thats the case, i would check your main engine ground to see if its loose or broken. if its loose or broken, then the engine will be trying to use another wire or cable to act as a ground. problem is that if its using another source for ground that its not going to be a large enough gauge wire or cable, causing alternator, starting, charging problems. and it might even burn up or at least seriously damage the alternate ground source i.e. the parking brake cable

[5literJeff]

Yes it does have two wires coming off the end connecting to the wiring harness (the two prong end) which is weird considering theres three wires coming off the alternator end.

The main engine ground wire is fine, its tightly connected from the back of the engine to the chassis and shows no signs of corrosion at all.

And yah I know the blue paint looks terrible on the alternator thats on there now but I will be replacing it anyway with a higher amp rated one soon. I just want to get this charging/wiring problem sorted out first. Dont want to put an expensive one on there only to have some wiring problem burn it up.

I was messing around today checking the voltage with key both on and off and I noticed something weird.

On this picture below I outlined where the three connectors are on the back of the alternator.



The terminal in red has 12v voltage with key on or with key off. I thought this terminal is only supposed to have voltage with key on?

The terminals in blue which I assume ones the ground and the other would be the voltage output from the alternator, I checked them and neither has any voltage with key on or off.

Did not check to see what the voltage was with the engine running because the damn thing wont crank now because the battery is drained so I have to charge it up (which I am doing right now heh).

Thanks again guys for the help, im getting so frustrated with this thing im tempted to get rid of it and forget I ever had it. Wiring/electrical just isnt my forte.

[OTreborO]

Is the alt light on?

Have you tried starting the car, and then removing one terminal from the battery to see if the car continues to run?

If the car continues to run, the alt is good, if it sputters/dies, it is using the battery to basically run the car.

[stang fanatic]

it still sounds like a corosion issue. problem with copper wire and corosion is the core of the wire allows the corosion to grow, so it takes forever to be seen unless you cut the wire open and look in the core.

[stang fanatic]

ok...manual shows 4 wires coming off of the alt, but two of them are the same color and are tied together. a blk/orange, and a yellow/white come off of a fusible link on the starter solenoid. a lt green/red wire, goes to the computer.

[5literJeff]

Hey guys just an update for anyone whos wondering the problem was the wire for voltage regulator power with key on was getting no voltage.

So I rewired the power from another 12volts with key on and shes charging fine now.

Thanks again for all the help!

[stang fanatic]

so that means one of the fusible links is is burned inside