Ok so....I put a 302 in my car about a month ago. i drove it around for about 3 weeks, suddenly the car starts acting lke the alternator is bad ....stereo goes on and off, headlights dim etc. after being driven for a while. Then the battery is always dead. So, i took the alternator off (brand new) and have it tested, its fine, but I'm pretty sure it was hooked up wrong so i found a diagram on here and fixed that....not sure why it ran 3 weeks like this, but ok. regulator is good. put a new battery on it. Car runs great for a few days, suddenly last night same symptoms. charged it all night, drove for 10 minutes today and he battery died. I have a ground from chassis to engine and from engine to battery. Does anyone have any idea whats wrong?? What confuses me most is that sometimes I can drive for days with no problems and sometimes it acts like the alternator isnt workng at all. Thanks!!!
when you said that the stereo turns on and off, thats a sign that the alt. is not the problem. there is probly a short some where that is messing with your eletical system. how do you know the regulator is good? i suspect that the regulator is the problem.
I just went through a similar situation myself so I grounded the CD player better (I did not install It.) and it still wasn’t charging. I then replaced the two fusible links going to the starter solenoid and the one below it near the alternator and the problem is now gone. I'd noticed one of the fusible links didn’t look right. I’m now wondering if one or two of them didn’t fry better because my battery didn’t have the juice to do a better job.
I had it tested at auto zone, it didnt test the way it should but we put a new regulator on and it tested the same. ven if the cd player is off i stll have the same problem.....and the cd player only starts tothat when the battery gets low. Once it starts restarting i know ifI turn the car off it wont start again.
i have seen bad wireing between the alt and regulator cause problems on fords with an external regulator. the fuesable link is a good idea to check. if they are bad it will be soft and maybe even streachy. you will want a multimeter and start checking the resistance of power wires and connections.
Try a differant battery. You might have plates shorting out. It can happen intermitently when you hit a bump.
I already changed the battery, I thought that could be it but it didn't help. I noticed the ignition feels really stiff for some reason....could it cause this? Remember, I never goes dead while sitting only while driving. Hmmmm
Run a hot wire to the coil and drive it that way. Don't foget the car won't shut off until you remove the wire. This will eliminate the ignition switch.
I say give this a shot Charge the battery replace the fusible links $3.99 each at NAPA. My car way giving me fits too these last few weeks of Summer. A co-worker and I just returned from Carls for a breakfast sandwich and he even mentioned my cars never sounded or ran better. Of course a freind and I replaced a lot of other stuff too, non electrical related.
Ok, so, I cleaned and checked all of my grounds. I put a meter from the ground wire to the negative terminal on the battery, and it reads 12V until I pull every single fuse. Ignition switch?
The ignition switch was what everyone said my problem was, although I'm glad it wasn’t. I sure you’ve already checked all the wiring around the voltage regulator, starter solenoid, and alternator for any exposed wire and I don’t mean just at the connecting points, I looked at mine through a magnifying glass and found wire exposed through this 36 year old plastic coating. I understand your frustration having just been through a like situation I spent last Friday from 2:00 p.m to 7 p.m. checking and replacing fuses, wiring, and fusible links. I'm so happy now I've driven it 2 days in a row to work!
You have the negative lead of your meter on the negative post and you measure 12 volts to the ground wire??? Is it connected to the battery negative post too or not? If it is connected then you have a bad wire if it is not connected you are getting the right reading.
Here is the complete guide to diagnose your charging system: Make sure the regulator is properly grounded - test it with a volt meter from the metal mounting flange to battery negative - it should be less than 0.5 volts. Check it with the engine off and running. Make sure the alternator belt is tight. Remove the battery + wire at the alternator and connect a 12v test light between the battery terminal on the alternator and the wire that you disconnected from it. If the light glows then replace the alternator - the diodes are shorted. If it doesn’t glow then proceed with the tests that follow. With the engine running…… With a volt meter (multi-meter on volt settings) place the Red lead on the alternator battery terminal and the black lead on the alternator case. You should see more than battery volts with the engine running. If you see a charge then move the black lead to the engine - the volts should be the same - if not then ground the engine to the frame and try again. If it still doesn’t charge then ground the alternator to the engine, Engine to the frame and frame to the battery negative. If there is no charge indicated, then disconnect the voltage regulator and jump a wire from the field to the battery terminal of the alternator and perform the test again. If it doesn’t show a charge then the alternator is bad. If it does show a charge then the regulator is bad - replace it. Note: most mechanics will replace the alternator and regulator together. They do this because They don’t trust their trouble-shooting skills or don’t know how to test them individually. It is not necessary to replace them both unless they both test bad. On the other hand the regulator is fairly cheap so if you want to replace them as a “matched set” and can afford the extra money - go ahead. It probably won’t hurt anything but remember - the box says the parts are new - not good. I have had many new parts that were not good right out of the box……
