Bugs in the electrical system??
 

So the other day I was on my way to work and the check engine light came on, got to work and check everything, fluids we're all good except for coolant which is always low 😕 When I got home I got a video of the flashes, OBD 2 really spoiled me I don't really deal with either but 2 is easier. From what I could tell from the flashes, it was Code 46 charging system. Anyways, I went to work the next day, drove in no problem. On the way home I could noticeably see ALL the lights dimming and the battery gauge was dying too. Got home just for it to die in the driveway. 🤦 At least I got home 👍

Checked the battery voltage, it was at 9 volts. It was an older battery that really didn't work with the truck. Just changed the battery 810 CCA. Put it and started it up just fine. The check engine light was still on though. Started checking grounds, the ground on the alternator showed 0, all the other grounds read 1. Long way of saying, I think I have a parasitic load somewhere? Something grounded to frame? How do I track it down?

"the ground on the alternator showed 0, all the other grounds read 1" - 0 what? 1 what? Numbers mean nothing unless we know what's being measured.

Do you have the factory service manual for your truck? There's a troubleshooting tree for no-charge on most years.

Also, what was the new codes? You should have a 12 for "PCM battery disconnected in last 50 power cycles" and a 55 for "End of codes"; I'm more interested in the OTHERS.

If you want them decoded, you can toss them to http://www.dakota-truck.net/CODES/codes.html (space between, like 12 46 55 will give all of them at one time) and see what it spits out.

RwP

My bad, I was checking continuity on the grounds, I'm thinking something is grounded out to the frame, not sure though.

I checked the new codes, I only had one, Code 41 generator field not switching correctly. I checked my alternator and there was hardly any magnetic pull from it. I'm planning on getting a new alternator on Friday when I get a day off. Another thing, I didn't get Code 12, is that a problem?

That might not be the alternator; I'd get the current one tested.

The field is controlled by the ECU normally, but that's not an uncommon failure; it's common enough that not only do they sell kits to convert to an external regulator, they even sell at least one kit that puts a resistor in so that the ECU thinks the field is working!

OTOH, if the field popped open inside the alternator, you'd also get that error.

I don't know why you didn't get a 12; but I wouldn't worry too much either way right now.

RwP

I actually was getting code 12 I was just misreading it, oops.

I got the alternator tested, AAP said it was bad. I got an new 120 amp. I got it home and installed, to find that it had a six rib pulley. So with that pulley my original belt looked like it was 1/2" to 1" too small. I got the pulleys swapped and put back in, the SAME belt just slipped over the tensioner. So now I have to get a shorter belt 🤦 oh well