First of it's a 2003 with the 4.6. I replaced a bad alternator a couple months ago and all was fine. On the way home today the radio volume went quiet and all the dash gauges were dead. Truck died and wouldn't even try to start, no starter clicking or anything. A couple times the gauges did the "sweep" but still no start, not even a starter click. Barely even operated the hazard lights. Towed it home and hooked up the jumper cables to my 7.3 Excursion. Truck started right up and I left if hooked up for a couple minutes hoping to get enough charge in the battery to get it in the garage. Unhooked the jumper cables, got in the truck and noticed the voltage gauge was reading nothing, tried to move it and it died. Hooked the jumper cables back up and let the Excursion charge it for about 5 minutes. Started, drove it to the garage (100ft) and backed it in. Noticed the voltage gauge was where it should be. Turned it off and back to run (didn't start) and the voltage gauge was reading good and it started right up.

Now, it doesn't appear that the battery or alternator is bad. Is there something else I should be looking at? I can take the alternator off and have it checked but don't want to go through the work if not needed to chase a ghost. Advance auto Tough One alternator BTW.

 

Your battery has not been charged enough.
Use a voltmeter at the battery and look for at least 15 volts after starting.
It would indicate if the alternator is working.
If less than 13 volts the alternator has a fault.
Charge the battery then have a capacity test done to check it's health.
Inspect all cables and connection for cleanness and tightness.
Go over the whole system for winter.
The dash voltmeter is nearly useless.
Good luck.

 

sounds like the alternator failed or could be the battery, but I doubt it. or a wiring issue.

 

Well, the battery is gone. It drops over 2VDC just by opening the door. Removed the alternator and will have it tested when I get a new battery. Acted like a grounding problem but all the grounds were good.

 

Replaced the battery with the proper size (one in it was too small) and replaced a faulty alternator. Now all is well.

 

Luna, you don't have to remove the alternator to test it? Just get a hot battery in the truck and start it. Use a voltmeter across the battery with engine running. If the voltmeter measures about 13.5 to 14.5 Volts, the alternator is working good.

Check the battery terminals closely and clean them or replace them.

Hope this helps.

 

Yea, I know you don't have to remove it but it's not that big a deal to remove it and while I was taking the battery to get tested thought I might as well take the alternator. I did use my voltmeter after getting the proper size battery in it and that's how I found I had a connection problem on the diode pack. I replaced the truck side connector but still had the problem so I exchanged the alternator. Advance Auto replace it with zero problems and it's charging correctly now. Thanks for the reply and insight on my problem.