Wiring Help Needed. Alternator Not Charging

[speeds5]

Car is an 1986 Carrera that was turned to race car a long time ago. Redoing the wiring. A lot of the chassis harness were cut out. Stock ignition key switch was removed and replaced with a simple toggle switch. Fuel Pump was directly wired with a toggle switch as well. Here's where I am...

1. Car starts (ignition on, fuel pump on)
2. Alternator doesn't charge.
3. #2 pin and #14 pin of the 14 pin connector red wires don't seem to have continuity with the positive terminal of the battery as tested with multimeter. I can't figure out where do they go.

A buddy is helping out and we think we need to rewire the connection from the male 14 pin plug and hook it to the battery + terminal.

Questions for the experts here.
1. Which of the two red wires in the 14 pin is the alternator charge wire? Is it both?
2. Do these two red wires go straight to the battery in the stock harness or do they connect to the battery through other connections (i.e. ignition wires).

any help really appreciated.

[timmy2]

Those 2 red wires in the14 pin connector are constant power sources for devices at the back of the car. (Come from alt positive)
The power to charge the battery is the alternator fat red wire that runs to tbe starter and from there directly to the battery positive terminal.
Check the blue wire from front to back as it is the one that tells the alternator to charge .
Also make sure your voltage regulator is good. (Take alternator to a shop to test)

[speeds5]

Thanks Dennis that makes more sense. That's your handiwork/engine harness by the way. Quality product.

I can trace the Blue wire (pin 11) in the 14 pin to the frunk where it is cut. The factory alarm was removed over the winter along with a bunch of wiring. Dumb move as I didn't realize this was a major part of the alternator., blue wire seems to go through it.

Can I simply hook a light to the blue wire and connect the other end to a positive terminal in the fuse box?

[timmy2]

You need the 4 watt lamp from the gauge. Buy in theory for testing yes you could do that. (With the 4 watt lamp)

[speeds5]

I was able to find the dash light from the gauge. The diode as well which I guess I never threw out.

Does this look right in terms of the diode direction and how it fits in the circuit?

[wazzz]

Diode should be in series on the other bulb wire, between Battery + and bulb.
However the battery + should be after ignition switch and not a permanent battery +. It should be the red/black wire coming from terminal 15 of key switch.

If your multimeter on the picture is set to diode test and reading millivolts, the diode is conducting and it is pointing in the right direction. Keep it this way, but move the yellow wire that is currently connected to the multimeter black probe to the red wire of bulb. Connect the other yellow wire of diode to Battery plus (after ignition).
Connect the bulb blue wire to Alt D+.
This is all better explained by a schematic. Do you have the Bentley manual? If so, refer to page 970-34.

[speeds5]

Thanks Gilles. That was very clear. Will report back when all hooked up and tested.

Originally Posted by wazzz

Diode should be in series on the other bulb wire, between Battery + and bulb.
However the battery + should be after ignition switch and not a permanent battery +. It should be the red/black wire coming from terminal 15 of key switch.

If your multimeter on the picture is set to diode test and reading millivolts, the diode is conducting and it is pointing in the right direction. Keep it this way, but move the yellow wire that is currently connected to the multimeter black probe to the red wire of bulb. Connect the other yellow wire of diode to Battery plus (after ignition).
Connect the bulb blue wire to Alt D+.
This is all better explained by a schematic. Do you have the Bentley manual? If so, refer to page 970-34.

[speeds5]

Dennis and Gilles, thank you for your help. Car is up and running and alternator is charging. The blue wire that was cut is energizing the alternator again.