Had two issues with my truck yesterday. Wife and I were going down the highway and the volt guage on the dash dropped to zero then the check guages light came on. Got the truck home and discovered a noise coming from under the truck.

Noise I heard was coming from under the truck next to the driverside frame rail right where the starter is. To me it sounds like the pinion gear on the starter was still contacting the flywheel. I barred the engine over by hand and could hear it clicking against the flywheel. I pulled the start and barred it over again and didn't hear the noise again. I looked at the starter while it was out and it looks like the gear isn't retracting completely into the starter allowing to keep some contact w/ the flywheel. I'm going to take the starter in and have it rebuilt this week.

Now the Alt issue, the guage went to zero while running. Code that came up was p1682, alt charging voltage is low. I pulled the alt and am going to take it to be tested. I noticed when Imoved my truck in the garage when I started it up the gauge was showing the alt was charging.

 

Update.

I took my starter and alt to a local auto/elec shop. Shop owner looked them over and did his tests. Alternator had a bad diode and the starter "Needed alot of help!" (His words). the starter had 209k miles on it. The real problem with the starter was the return spring on the pinion. It lost tension and was about half the length it was suppose to be. So both the alt and starter got full rebuilds. Installed the rebuilt units in my truck the other night and they are working good now. Truck is charging and no more noises.

 

Good to hear you got it sorted.