I've got an 02 excursion 7.3 that has been plagued with alternator problems. I'm now on my 4th alternator. I just got back from a 1000 mile trip and was able to limp it home on batteries and a brand new autolite alternator. The trip down to LA/San Diego went well but the following day I noticed a humming sound. I'm familiar with this humming sound being related to the alternator so I immediately pull out my multi-meter and I probe both batteries while its running. I get a 12.20v. Had my buddy rev it up and the voltage didn't move.
I ran to Kragen and had a choice between rebuilt and new. I went new for $25 more and a lifetime warranty. Replaced the alternator in the Disneyland parking garage, took 10 mins. I start her up and i get 12.7v. (I just today found out that there is a 60 second delay in the alternator turning on). I didn't know that at Disneyland but I shrugged it off and was happy I was getting a partial charge. I didn't want to sweat it too much and have my family worry so I closed the hood and drove down to San Diego. No issues, I was up and down Rancho Santa Fe/San Diego hills with absolutely no issues until the trip home yesterday.
Just as I peak the 4400ft 6% Grapevine pass my battery light starts flickering. ****! I make it down the grapevine and I pull over. I probe the battery and I see 12.02v. I've got about 300 miles to go I decide to run her home and not shut down. I pulled over the next 100 miles and I see 9.05v. At this point my windows/radio/cigarette lighters aren't working. I'm thinking I might not make it on just batteries alone so I ask for the nearest parts store and it's 30 miles away. I decide to call Aaron (nation) who is about the only powerstroker i've got a number to try and diagnose. As I hang up after leaving a message, I notice my a/c blower get stronger. I step outside and probe the batteries and the alternator is giving it 12.6 - 12.7. I decide to run the 200 miles all the way. The battery light stays off up until 2 miles from home and it starts flickering again. We made it home.
I woke up this morning. Disconnected all battery wires and load tested the battery (trying to keep it simple at this point). Batteries both tested well on a 10 second load tester. Cleaned all 4 terminals and connectors which were somewhat dirty. I start her up and i get 12.7.... after 60 seconds it jumps to 13.90v at the alternator and 13.84v at the driver side battery. (Per nation, I check the 2-wire harness running to the alternator and all seems ok, but I have yet to peel away the entire loom that runs along the engine block to check for any open/shorts.) So the battery light is gone and i'm now getting 13.8v on a cold engine. I get in to rev the engine and when I pass about 1800rpm revs the battery light comes on and flickers and then shuts off as the rpms drop. Give my pop a call and he says could be the belt slipping. I kinda agree but I don't see the belt looking loose when I rev it. No belt bounce or anything. What do you guys think? Shot brand new autolite alternator?
Thanks in advance.