longsix Posted January 14, 2019 Share Posted January 14, 2019 hey guys, on my ,86 f150, 4.9l, the battery drains over a few days , when not in use. i changed the altenator, checked voltage, engine running(12.3v). recharged battery over night ,checked voltage(12.8v). cranked truck, checked voltage(12.4). new alt. has the plug built in, so i checked all connections, they seem ok. what could i have overlooked? thanks in adv....longsix Link to comment Share on other sites More sharing options...
Gary Lewis Posted January 14, 2019 Share Posted January 14, 2019 Your voltage should be 14.0 or more when running, so if it is 12.3 or 12.4 your alternator isn't working. By "has the plug built in" do you mean it doesn't have a regulator on the fender? If so it is the 2G alternator and you may have a wiring problem. You might want to read this TSB from Ford on it and check your wiring: http://www.garysgaragemahal.com/96-21-04-2g-alternator-repair.html. Link to comment Share on other sites More sharing options...
Steve83 Posted January 14, 2019 Share Posted January 14, 2019 Post several pics of the alt, its wiring, the battery terminals, the starter relay (on the inner fender), the body/frame/engine ground points... Read this caption & follow the link for instructions on embedding pics in your posts: https://supermotors.net/getfile/72354/thumbnail/doorsticker.jpg Link to comment Share on other sites More sharing options...
Recommended Posts