A week or so ago, I posted a question about a voltage regulation
problem on my '69 2000. Well, I finally figured it out and thought
the list would appreciate the input. I had changed the regulator and
no joy. Downloaded various schematics and those were helpful to trace
wiring and voltages around the car. I noticed a number of harness
connectors looked corroded . What finally was the giveaway and led me
to the right spot was when I opened up the voltage regulator and
measured voltages on the tie points for coils and wires inside the
regulator following the schematics. The ground point measured a
fluctuating voltage relative to the battery - terminal of anywhere
from 0 volts to +6.5 volts. The voltage on the high side of the VC2
coil should have read 1/2 the battery voltage but was reading full
+12.5 volts so I knew there was a bad ground to the field coil of the
alternator. I tried to remove the plastic 4 wire connector at the
alternator and the wires fell out. All the wire connections at the
crimps were corroded through and the wires were brittle.
Now I had to figure out which wire went where on the connector. I
took a look at my non-running '68 2000 for guidance but the wires
were all replacements and whoever redid the harness did not observe
the correct wire color code so that was a bust. I wound up using an
ohm meter to find which pins were for the field coil on the
alternator (low resistance, no diode front/back ratio). I then took
an educated guess as to what should go where relying on my quick
glance at the wires before they all fell off. With the battery
disconnected, I pulled the brass crimp connectors out of the
connector that plugs in to the alternator, cleaned them up, stripped
the old wires back to find good copper, and recrimped the old
connectors to the stripped wires, then soldered them to strengthen
the connections, then pushed the connector pins back in to the
plastic connector body. After three unsuccessful tries with different
wire combinations, I finally found the combination that worked. I'm
feeling pretty good now as this is my first real repair on this car
and I'm a little rusty. I will probably have to go back and redo a
lot of the connectors. I'll find the right new connector pins and
redo many of them, and will most likely have to replace a lot of wire
too as the old wires are corroded in a lot of places.
While I was trouble shooting this problem, I also beefed up the
chassis ground by adding a large ground strap between the engine and
the frame rail. I made this out of an unused battery jumper cable and
big beefy crimp connectors. This helped brighten the headlights
considerably. That was a direct result of input from the list. Thanks
to all who posted helpful tips. I'm now going to take the car out for
a spin while I can.
Dave Corbitt
Summit, NJ
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