Joined: Thu Jun 25 2009, 11:41PM
Location: Santa Ynez CA
Posts: 105
so i just replaced my alternator, voltage regulator, and fusible link, and now my ammeter is even jumpier than before. at idle it is steady, i can operate the power seat, windows, lights and all that without the gauge moving more than 1/8th inch or so. when i up the idle, 1500 rpm or so, and move the seat, the ammeter nearly pegs towards the "C" side. likewise when i turn on the headlights and hit the brakes the meter dips way down on the "D" side. what gives? it's a 68 FuryIII 318.
Joined: Sat Sep 23 2006, 04:30AM
Location: Sharpsburg, GA
Posts: 924
The voltage regulator is not regulating. You are getting way too much voltage when it revs up and not enough when it is idling with a load. If you have a volt/ohm meter, measure the voltage output at the alternator's black wire at high revs. It should not go over 15. If it's going to 17 or 18, then You need to fix it right away before it damages things.
Make sure the Regulator case is grounded the the firewall. Make sure the field wire (green wire) is not shorted out to another wire.
I would do the MADD wiring conversion and replace that fire hazard ammeter with a good quality volt meter--they work much better and tell you if your system is charging enough, while the ammeter just shows that there is current flowing.
If you don't want to bypass the ammeter, at the very least run a thick 10 gauge wire from the alternator stud to the starter relay battery post (be sure to use a 12 gauge fusible link on the starter relay end). This will take most of the current load off the ammeter and prevent the car from burning to the ground. BTW, more old Mopars ended up in junk yards because of electrical system problems than any other reason.
Joined: Thu Jun 25 2009, 11:41PM
Location: Santa Ynez CA
Posts: 105
gee, that's comforting.. there could be a ground issue with the regulator case, both screws seem to be a little stripped, they get tight, but not as tight as i'd like them to.
Joined: Thu Jun 25 2009, 11:41PM
Location: Santa Ynez CA
Posts: 105
i like the idea of running a wire from the alternator to the starter relay. so run a wire from the alternator stud, to the stud on the starter relay, that connects to the + battery terminal, yes? the new alternator i just installed is beginning to make even more noise than the old one did so i'm thinking i'm going to return it for another.
Joined: Fri Jun 04 2010, 10:30PM
Location: Illinois
Posts: 464
Ah yes, the part store "rebuilt" alternators that aren't any good. I've got a local rebuilder that's been in business for 40 years that I trust. They go through it and replace everything plus you get your old case back. Glass beaded for a little extra $. Or they have quality ones on the shelf if you're in a hurry. I'd look for someone like that in your area. And a good ground is a must!
Hey Kraut, if you leave the connection to the ammeter and add the 10 gauge by pass, will everything else still work right? I'm assuming so and that power will flow to them on an as needed basis. I'd like to leave my ammeter operating, add a volt meter, and decrease the likelihood of a melt down. (Had one on my 68 300 and got lucky damage was limited)
As long as you add the big fat wire you can leave the ammeter hooked up-the big wire will carry most of the load. I would check the connections in the bulkhead if they look okay coat them well with dielectric grease to keep corrosion at bay-if they look questionable then get rid of the connectors and solder them together. <span class='smallblacktext'>[ Edited Fri Dec 31 2010, 11:29AM ]</span>
Joined: Thu May 01 2008, 11:15AM
Location: Chicago,IL
Posts: 2868
Your ammeter will not work correctly that way, that is, not as intended. Depending on which side of the ammeter is requiring more power, the ammeter will read differently. If you put the lead in as Kraut shows, the ammeter is completely just a gauge to tell you which way current is running through it and in no way tells you anything helpful about the electrical system. For that reason, I would advise bypassing it so you and other potential drivers don't get confused.
Joined: Thu Jun 25 2009, 11:41PM
Location: Santa Ynez CA
Posts: 105
Awesome diagram, and thanks for all the advice, very helpful. the reason i went with the napa rebuilt was the price was right, but i guess you get what you pay for..