2003 f150 king ranch . Battery light came on and I change the alternator. That was about 6 weeks ago now same problem. Battery light is on again. Any suggestions.

 

How old is your battery? it may be bad. Also, check all the cables attached to the battery and the connections to the wiring of your truck. Clean any corroded connections and make sure all are tight. Also, check the wiring harness connections to your alternator and make sure they are clean and tight. Use di-electric grease (available at parts store for less than $5) on electrical connections to ensure you get a good connection.

 

Poor quality alternator rebuild.

 

What made you jump right to the Alt ?? like stated above could be your Batt...did you have either tested ??

 

Take the vehicle to Auto Zone for a free charging system test. Call before to verify they can do it.

(I think the previous mention of dielectric grease on connections really meant to suggest "conductive grease" like No-Ox-Id on connections. Dielectric means insulating and it will prevent a good connection. Never apply dielectric grease except on boots, orings, etc. when you want insulating effect. No-Ox-Id will protect and provide good conduction of electricity.)
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