"Check Charging System".. Help Please!

[Mackelcha]

Ok here is the situation: 2001 Lincoln LS 3.9
I have checked the other threads to seek an answer but not seen others with similar symptoms posted.

Warning light "check charging system" comes on while driving home. Having experienced this in other models I was sure to think I would soon be stranded on the highway waiting for a tow. However, I made it another 35KM without a problem.

1.Using a volt meter I checked the batery an got a reading of approx 12.3V with the ignition off.
2. After starting the car the battery was reading 11.5V as it was running.
3. I opened the throttle a little to kick it up and the volt meter still had not changed from the mid 11V range.

So seeing this I assume it is simply the alternator. I purchased and replaced the alternator.

1. Start up the car and the warning light returns.
I let it run for a while thinking it may simply need a charg to raise the voltage.
2. Battery with ignition off remains around 12.3V
3, When car is started batery drops to 11.5V
4. I open the throttle close to the idle rev limiter and the voltage jumps to 13.7V and the light remains on.

I know I should be over 14V but am not sure where to focus my attention.
I have been told perhaps it is the voltage regulator; I am not sure if the LS has an independent regulator and if it does where it is located? Unfortunately my local automotive suppliers do not have manuals for the LS.

So my questions is, with these symptoms where should I foucs my attention?
-Did i recieve a bad alternator? (bought from ford, brand new)
-Could a bad connection be causing the lower voltae readings?
-Is my battery shot and simply not accepting a full charge?
-Is there an independent voltage regulator and could that be the problem?
-Anything else that I can not think of.

Any help or direction would be greatly appreciated.

Thanks

 

[eastcoastLS]

Any audio/video equipment hooked up in this vehicle?

 

[owlman]

I only have a manual for 06 so it might be different. It says the regulator is in the alternator and cannot be replaced separately.

There is also a wire that goes to the alternator telling it to turn on (when the motor is on) and turn off (when the motor is off). Maybe that wire is loose/damaged for you.
Even if that wire is damaged or not sending the right signal through it, when the motor revs over 3000 rpm, the alternator turns on and functions normally as a limp-mode. Does your voltage change right around 3000rpm? That could be it! Or I could be sending you on a wild goose chase
And supposedly 13-15V is normal.

 

[Mackelcha]

The vehicle is pretty much stock, the only thing electronic outside of factory is one of the electronic anti-rust modules that the original owner had installed.

 

[Mackelcha]

After I had the reading of 13.7 i checked all the connections, cleaned up the power connection to the alternator to be sure.

I believe it would have been around 300RPM but not 100% sure as i was doing it manually from the throttle body.

The lights get brighter and the battery voltage jumps as well.

Individuals have told me that the battery voltage should spike as soon as the engine is turned on; I checked this on 3 other vehicles in my driveway and that is what hapened.

My main concern is that the warning light remains on, and on all other vehilces and conversations have told me I should be above 14V.

I do not live too close to town and want to be sure everything is fine before I continue to drive it on a regular basis as I do a fair amount of driving.

 

[lseguy]

If it's the original battery, I'd go ahead and replace it with a new factory replacement. If that doesnt fix it, it's not like you've wasted money..6 years for a battery, and it's about due anyways.

If the battery doesn't resolve the issue, I'd take it in for a full diagnostic check vs randomly throwing money at it yourself.

When the engine is revved to about 2krpm, the voltage should be over 14 volts. And even at idle, with a/c, brights on, etc...it should always be above 12 volts.

 

[Mackelcha]

ok, thanks guys.. I guess ill try the battery route and let you know...

And i do agree, the last thing I want to do is be randomly be throwing money at it.. but then again i figure it would have cost the same after letting them "diagnose" so it is always a learning process.

 

[joegr]

It's not going to be the battery. To assure yourself, you could swap in a battery from one of your other cars just to try in the driveway.

 

[Mackelcha]

joegr, you were right and that would have been amore sensible plan.

I changed it and got the same result.
- 11+V when initially started
-13.7V when rev'ed up
-Check Chargin system still on

If the alternator is bad, would it still be putting out voltage?
Do some vehicles have a dely until the alternator kicks in?

Thanks again for the replies... by far the most responsive forum I have been on.

 

[joegr]

Yes, it could be the alternator with those symptoms, but it is also a good chance that it is the wiring to the alternator. Many auto parts stores can load test the alternator, but you'll have to take it off the car for that. Before doing that I would check the connections to the alternator. The problem is likely to be one of the connections on the three wire connector.

Wire 1 - White/Red - should be 0V with the key off, 10-14V key on, engine off, and 1 to 15v with the key on and engine on.

Wire 2 - Gray/Red - should be 0V with the key off, 0V with the key on and engine off, and 1V to 8V with the engine running. Odds are its this wire or the next one.

Wire 3 - Red - Should follow battery voltage anytime the key is on.

 

[owlman]

Wire 2 - Gray/Red - should be 0V with the key off, 0V with the key on and engine off, and 1V to 8V with the engine running. Odds are its this wire or the next one.

Yeah that's the one I was talking about, where even if that wire is damaged, if the engine is turning over 3000rpm the alternator will work (which sort of sounds like what you are seeing).

 

[Mackelcha]

Problem Solved..

Thanks for the help guys...

It was plug going to the alternator.

I puled the plug and started it and had the exact same voltage readings as before.

After playing with some mirrors to try and see the inside of the connection on the alternator while it was still in the car, I was able to see one of the prongs bent so it was not making the connection inside the female end of the plug.

So I fabbed up a mini pry bar and was able to (more by luck) re-align the prong with the alternator still in the car.

Problem solved.

If I bent it somehow putting it in, or if it came that way from th dealer who knows.

Either way thanks for helping me isolate the area to focus my attention.

Cheers!

Cameron