I have a 2002 7.3 diesel super duty with a charging system problem.the system does not start charging as soon the vehicle starts, It could take a up to 2 or 3 minutes before it will charge and then the output is @14.3 volts.
Has new batteries, new alternator, cables clean. Whatis left to check to fix problem

 

You might have better luck posting this in the super duty/ F250 forum. Good luck.

 

I would take the alternator in to be checked. It is not uncommon to get a bad alt out of the box. But first check the belt to make sure it is not starting to slip. Could be when cold...it slips until warmed up then grabs enough to spin the alt the right speed. Also make sure ALL pulleys that the belt goes over turns freely and doesn't bind.

 

belt ok,alternator ok, does not matter if the truck is warm or cold

 

The charging system isn't magic. It's the alternator....just the alternator......period. It either charges or it doesn't. The only thing that governs the alternator output is the engine speed/belt speed. Nothing outside of the alternator governs the output or switches it on or off.

I agree with the above recommendation, you have a faulty alternator.

 

Are you sure you're not just seeing the effects of the glow plug system at work? The system voltage will be down a volt or so until the GP's kick off. Then the voltage jumps to normal. Try testing it when it's good and hot and see if the time delay is much shorter.

 

Good point, FD.

 

my 05 psd will do this ever once in a while. usually chareges in about 30 seconds. i belive in eaving sleeping dogs lie.when it dosent charge at all, you can find the problem.