2000 F350 V10. Go to start truck and it's dead. Put my jump pack on it and it starts right up but battery light is on. Check with my meter and I only have battery voltage. Ok, bad alternator. Slam a reman in there and the light is now out but still not charging. Alternator has a three pin plug and a single white wire going back to the alternator. I have voltage at the one terminal on the 3 pin connector. Battery wire going back to solenoid only has battery voltage. The white wire I think controls the light and the green wire controls the gauge? Checked all my grounds, cleaned up the battery terminals and charged up the battery. Am I losing my mind or did I just buy a new defective alternator?
Does the battery start the truck now? Maybe the battery has died and has a hard short internally, so it looks like it isn't charging?
green is light. white/black tracer goes to small square hole with a single wire plug in connector. yellow is sense. The two end wires in the three wire plug should both have voltage with the key on. often there was a problem with the connection points of the white wire. It may be your problem. Make sure there is continuity at both ends of the white wire. Often the small prong in the small square would get bent out of the way too. If the wires check good try another alternator.
Very common for Fords of that era to have fuse inline on the main charge wire to the battery. The fuse is probably fine, but the connectors on both sides of the fuse are probably exploding with nasty green corrosion. I've fixed that a dozen times. Run a big jumper from the back of the alternator direct to the battery for a quick diagnosis.
A friend had a very similar problem on a Saab 9-7x (Chevy Trailblazer in a Swedish dress). It was a bad cell in the battery. Patrick
So both outer wires have 12v with the key on. White wire has continuity. It's gotta be a new defective alternator. I sent it back to Rock. Now I have to wait
It may be a faulty alternator because of the high quality parts now days, but check all connections first. You can still have 12v on a wire, but if several strands are broken or the terminals are corroded, it can't carry any amperage. Use a halogen bulb to make sure the circuit can carry amperage. If there's corrosion or multiple strands of wire broken, the bulb won't light.
I think I'm losing my mind.. I sent back the reman alternator back to Rock auto and they send me another. Second reman alternator- battery light on, not charging. Missing the 6v on the white wire. Returned second reman alternator to rock and decided to try one from the local AutoZone Third alternator from auto zone- battery light on/ not charging. I took the truck to my friend Gary's shop. He's a far batter mechanic than I am. We went through everything. Not getting the 6v from the white wire. He tells me, "it's a bad alternator. So I go back to AZ and exchange alternator #3 for Alternator #4 Alternator #4- battery light on/ not charging. No 6v at white wire. This alternator has an 800 number to call for tech assistance. I tell the guy everything and he concludes I have a bad alternator. What the F is going on? Now I'm going to shoot the lock off the wallet and go buy a BRAND NEW alternator from Advance auto and try one more time. If this one doesn't work, I swear I'm going to set this truck on fire
We checked everything. Went through every fuse, checked every ground, checked the connections at every relay. We have battery voltage at B+, 12v at the two outer wires on the three wire connector just like were supposed to have. Just missing the 6v which activates the alternator. Battery tests good.
Did you try full fielding the alternator? A common mistake is not having the plugs pushed all the way in. I'm pretty sure there is no voltage at the white wire until the alternator is charging
I've seen the wires push in on the plug. Seems like you have voltagecwith a meter but whe you plug it on alternator it doesn't make ther connection. They sell those plugs,replace it.
I would take the power wire off of the back of the alternator. Use a halogen bulb between the terminal that you removed and ground. Do that with any wire that should have power or ground. You could have a bad connection in a terminal that is not able to be seen. It will still read correct voltage and it may even ohm out correctly, but it can't carry any amperage. I find it hard to believe, even with today's crappy parts, that you got 5 bad alternators.
Got a motorcraft pigtail and soldered it on. Also replaced the white pigtail. Battery light still on. Only battery voltage at B+
