kingbobdole Posted October 6, 2014 Share Posted October 6, 2014 (edited) So I have two problem children. First is my daily driver a 79 fe 1600. Yesterday, when I shut if off, the charge light stayed on, and the fuel pump continued to run. If I unplug the alternator all of this stops. Also the wipers work with the car off as well, but it has always done that. Second car is my 78 brat. It has never charged. I put a set of brushes in the alternator, and a new voltage regulator, but no dice. Light works on the dash and I'm thinking it also just needs an alternator. Thoughts? Thanks! Edited October 6, 2014 by kingbobdole Quote Link to comment Share on other sites More sharing options...
turbosubarubrat Posted October 6, 2014 Share Posted October 6, 2014 Use a multi-meter on the battery while the engine is running to see if the alternator is putting juice back in the battery. It should be slowly going up to 14v or a little more. Or you can take the alternators off and get them tested at a parts store for free. Quote Link to comment Share on other sites More sharing options...
naru Posted October 6, 2014 Share Posted October 6, 2014 I suspect a leaky positive alternator diode in the 79. I would use the "diode check" function of a multimeter to verify. I would check the 78 alternator by bypassing the VR. Unplug the VR and jumper 12V to the F terminal in order to supply full field current. Run at low speed and check the output voltage. Slowly increase engine speed. Beware of excessively high voltages-increase speed slowly. Good luck. Quote Link to comment Share on other sites More sharing options...
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