My '91 ford festiva will start and run when jumped but will die when the lights or radio is used replaced the altnator already and batteriy is good idk whats wrong can anyone help
You or someone will have to figure out why your new alternator is doing absolutely nothing. Not only is it not putting out enough power to run all the car's electrical systems, it is also not charging the battery, so you could start it next time off the battery and not have to get it jumped. With it not working, the car has to use battery power to run everything, and when you use lights, or radio, or any accessory, the battery runs down even quicker.
One reason alternators don't work is loose or poor connections between the battery and alternator. You could remove your battery cables (check them, if they look old or worn badly, replace) from the battery (negative first) and clean the cable ends and the battery posts till the metal is shiny clean. Do the same for the negative cable to frame ground point. Then check the big cable end on the starter, make sure it is tight. Put the cables back on-positive first, negative last, then move to the alternator and check the connections there for a clean tight connection. A couple of other ground points you could check is the engine to frame ground-somewhere on the engine is a ground strap bolted to engine metal and the other end will ground on the car frame or on the firewall in back of engine. If this ground is lost, strange electrical problems may result. One more ground: often the engine and computer wiring harness will have a ground wire coming out of the harness-a short wire-and may be grounded around the top of engine-many cars do have this visible ground, so check for it and check if a good ground.
If you do all this, and still no help, cheeck all your fuses in the under hood fuse block-sometimes there is an alternator fuse there, a big maxi-fuse. Check if good, check all fuses. If no help, you likely need a mechanic or shop to figure it out. Good luck. Hope you find it.
Jan 07, 2013 |
1991 Ford Festiva