Won't stay running
 

Hey guys, so I new to this and kind of a newb to working on cars. I know some stuff but not alot. so I have a 93 Dakota with the 5.2 in it. A while back I had a real bad coolant leak. Like a gallon of coolant a day bad. Short story we pulled the engine and it end up being a freeze out plug in the back. Before we pulled the engine she ran like a champ. Plenty of power and super fun to drive. After getting everything put back together it won't stay running and it threw code 41. I replaced all the gaskets down to the head, new oil pump, radiator, rear main seal, plugs, wires distributor cap, tps sensor, and 2 other sensors. I don't know what it could be. I checked for vacuum leaks and nothing. I'm over $1000 into this truck and at my end with it. I don't want to get read of it but I have no clue as to what it could be. Some body told me it could be the alternator going weak and not giving the computer enough juice to function. Any ideas

Code 41 is whining about the field not switching. (alternator field coil) Check connections at the alternator, and see what your volt gauge has to say. Over or under voltage will make it run really strange.

So do you think it could have something to do with the alternator

That's what the code says. Field not switching. So, its either staying on, or staying off. If it is staying on, then voltage will be high. If it's staying off, voltage will be low. You should see right about 14-15 volts at 1000 RPM.

The code came on but after driving it, it went off. I have noticed that the battery isn't holding a charge and it's my 2nd brand new one

What's the volt gauge have to say? Is not not charging? Or is it just going dead overnight? (some variety of draw.)

11.5 volts, it's going dead over a couple days. I had to started today, after about 5 starts I had to jump it

Alternator is not charging. Check and make sure all the connections are clean, and tight.

Could it be a bad ground

Bad ground, bad positive connection at the alternator, bad field connection, oxidation on connectors, slipping belt ... It CAN be a lot of things.

Before I sweated too much, I'd get that alternator bench tested, and checked all my fusible links to make sure that none are popped.

I'd also check all my grounds, including the ones for the battery.

And THEN I'd check the field circuit, since on most (all?) of the Gen1's the ECU controls the charging.

If it's the ECU failed, that's not super critical; there's instructions all over the net on how to convert to a stand-alone regulator.

RwP