The "Check Charging System" warning that won't go away...

[bgrattan]

Update, I pulled the alternator out again (by the way, is there a way to get it out without taking off the radiator hose and spilling some anitfreeze) and checked the three-pin plug, blew it out with an air compressor, reconnected, and confirmed the positive voltage connection was nice and tight. I also trace the signal wire to another plug and cleaned that one.
All this had no effect.
But, I was able to take it on a four hour drive with no problems at all--voltage stayed between 13.8 and 14.2 with brights on.
The warning still comes on every time I start the engine though. I'm going to have to check all the fuses and connections other than right at the alternator.

 

[Hamfisted]

Do you remember what brand of alternator you used? A lot of people have this problem with the cheaper brands like Advance Auto and such. Just wondering. Like they rebuild the alternator as far as brushes and bearings, but skimp on the circuit board that communicates with the PCM.

 

[thesavo]

Here are some excerpts from the 2005 Service Manual DVD. It's not the same year as yours, but should be close enough. It would appear that the generator PCB communicates with the PCM with Pulse-width modulation. That is harder to get a reading on. You could check that you have good continuity with the generator/PCM pins. The PCM uses a serial bus to talk to the Instrument cluster.

1. Charging system diagram.
2. Ford ED/ED Diagnostic manual for the charging system explaining where to look for issues based on the DTC for P0622.
3. Pin out diagram where the Generator signal wires terminate at the PCM.

Attached at the bottom
1. references the PC/ED manual. That has a further entry for P0622. This references another set of instructions, called HY.
2. Workshop manual for the charging system.

I hope some of this info is helpful.

 

[TomB985]

Good information from the Savo, I've attached the relevant service manual info from the 2006 manual.

 

[CldLk-Tim]

My 2006 KRanch has same mileage 194 but in metric, its a Canadian thang "eh".....The cable check idea was good but also checking the "Grounds" and i dont mean playgrounds.Pull Fuse # 7 5a while truck running "surprise"...Youtube fusebox link description scrolls on right >>>


it may reset that gremlin....

CldLk-Tim
Ammo Covid Currency of the Near Future

 

[bgrattan]

SOLVED!

Hamfisted was correct, I did buy the alternator from Advanced Autoparts and... that was the problem.
I ended up taking it to the local shop (Northwest Brakes and Undercar, Happy Valley, Oregon) and it was a puzzle for them until the looked up the part number of the alternator. The ORIGINAL part number, not the one on the sticker after it was rebuilt. It turns out it was a 150A alternator--not 110A. Apparently, that confuses the onboard computer which then throws the error. I was able to return the alternator and bought a new one from Rockauto Protip: look for alternators at warehouses near you in order to save a bundle in next-day shipping.
Anyway, I put in the new alternator. No errors. Charging fine.
To recap:
The original alternator was definitely bad.
The original battery was probably bad (just because I had deeply discharged it multiple times).
The first new (rebuilt) alternator was the wrong one.
With a new alternator and a new battery, everything works.

For anybody who finds this in the future:
Signs you've got the wrong alternator:
-battery charges just fine
-"Check Charging System" comes on approx. 30 seconds after turning on engine every single time.
-If you disconnect the connector the branches off from the alternator (C192 in the 2006 Wiring Diagrams book) you can measure a signal with a multimeter; this doesn't mean it is the *correct* signal. With it disconnected, the error still occurs the same way.

It appears as though having the computer confused by the alternator was causing the engine to run a little funny too--not like it was a misfire, but kind of like that. I'm still investigating that.

 

[GAINMOB]

I put a 300a h/o alt directly on my truck... no charging system warning... for years...i now have a 370a directly on charging at 15.1v and no charging system warning

Sent from my SM-G965U1 using Tapatalk

 

[thesavo]

SOLVED!

Hamfisted was correct, I did buy the alternator from Advanced Autoparts and... that was the problem.
I ended up taking it to the local shop (Northwest Brakes and Undercar, Happy Valley, Oregon) and it was a puzzle for them until the looked up the part number of the alternator. The ORIGINAL part number, not the one on the sticker after it was rebuilt. It turns out it was a 150A alternator--not 110A. Apparently, that confuses the onboard computer which then throws the error. I was able to return the alternator and bought a new one from Rockauto Protip: look for alternators at warehouses near you in order to save a bundle in next-day shipping.
Anyway, I put in the new alternator. No errors. Charging fine.
To recap:
The original alternator was definitely bad.
The original battery was probably bad (just because I had deeply discharged it multiple times).
The first new (rebuilt) alternator was the wrong one.
With a new alternator and a new battery, everything works.

For anybody who finds this in the future:
Signs you've got the wrong alternator:
-battery charges just fine
-"Check Charging System" comes on approx. 30 seconds after turning on engine every single time.
-If you disconnect the connector the branches off from the alternator (C192 in the 2006 Wiring Diagrams book) you can measure a signal with a multimeter; this doesn't mean it is the *correct* signal. With it disconnected, the error still occurs the same way.

It appears as though having the computer confused by the alternator was causing the engine to run a little funny too--not like it was a misfire, but kind of like that. I'm still investigating that.

Nice . Glad you got it sorted and it wasn't anything to major.