hi all, i have been reading a lot of posts about the alternators making noises on these trucks... well, mine is different than the other peoples noises in that mine will do it when warm(today was almost 65), and it does it even in park. it is just a whining noise, and you can hear it outside of the truck also. anyone ever have theirs do this? if i bring it in to the stealership, im not sure if it would qualify for the upgraded unit since its not under the same conditions as the other people have noticed. thanks !!!

 

Hi. How have you determined that the alternator is making the noise? Maybe I can help.

 

They whine when they are working really hard, perhaps you have some electrical draw when you are away from the vehicle, or possibly a defective battery. Most auto parts stores can do a quick electrical systems test to pinpoint the problem. The auto parts stores are usually free, the dealer will most likely charge you 1 hour labor for a 5 minute procedure.

 

it doesnt always make the noise.... but i am sure it is the alternator... i mostly notice it when it is just started up... we arent very cold... like maybe 50's at night, but that the only time i notice it. the battery seems just fine, but then again i havent load tested it yet... never thought of doing that.

 

Sounds like Matts72 knows this stuff. When I used to have one of those big old scopes I could look at the wave form from the alternator output. You could see a bad diode from the shape of the wave. I noticed that almost all the ones with bad diodes would sing (my term) when under a load. The heaver the load the louder it would sing. They can last a long time doing that and still keep a good batt. charged.