Battery Light (P0620 Generator Conditions Circuit)

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Wilson

Member
Joined
Jan 4, 2017
Posts
18
Reaction score
4
Location
Nevada
My 2003 5.4 was throwing up the battery light on the instrument cluster with a "Check Charging System" in the message center.

The light would randomly come on and go out.

Yesterday the light came on, and stayed on.

Also threw a CODE P0620 into the computer.

I did the Ohm reading test, and instead of 1.2 - 1.6 ohms as suggested by the previous article Part I, the Ohms were read at 960. So Sum Tin Wong so to speak.


I also have replaced the alternator and battery and alternator cable as per a Ford TSB on this subject.

Two of the alternators that I replaced were bad out of the box.

Third one from NAPA (Gold) worked for a while, and now the above. Going back in to NAPA to exchange and try again today.

I seem to be following the pattern from the Story Part 1 and Part 2.

Can't believe that it is that hard to get a decent rebuilt alternator.
 

Wilson

Member
Joined
Jan 4, 2017
Posts
18
Reaction score
4
Location
Nevada
On the way to NAPA auto parts, the battery light remained on full time, but the battery gauge needle did not go down indicating discharge.

Picked up the new alternator (no questions asked).

Drove home to install it, and there was no battery light on in the instrument cluster, and no message in the Message Center.

Huh ? ?

Gonna change out the alternator regardless and will report back.
 

Wilson

Member
Joined
Jan 4, 2017
Posts
18
Reaction score
4
Location
Nevada
Ok got the fourth alternator (2nd from NAPA).

Everything works fine. Previous alternators were 135 amp units. Did not work with my Expedition. I have no
idea why. Installed a 110 and everything worked perfectly. 110 was the original spec. All the guys at the shop said
no problem to install a 135.

Seems to me that my computer did not like a 135, and when I installed a 110, everybody happy !
 

Latest posts

Members online

Forum statistics

Threads
53,391
Posts
500,597
Members
46,798
Latest member
geovanni
Top