Another Alternator Issue

[Al 77 280z]

Hey Guys,

During the process of getting my 77 280z running I have ran into an issue. The car runs great but it is only running on battery power, the alternator is not charging. I first suspected that the alternator was just old and worn out so I followed the ZX upgrade procedure and eliminated the stock voltage regulator. I completed the install and am still getting the same results (no charging). During my research I have found that most people have some sort of diode on the back of the alternator connected to the voltage output wire and grounding to the housing.  My car does not have this diode. I also am getting battery voltage at one of the T connector wires. Im stumped currently so any input would be great.

[Al 77 280z]

A few reference pictures

 

Edited April 6, 2016 by Al 77 280z

[Zed Head]

25 minutes ago, Al 77 280z said:

 

 I also am getting battery voltage at one of the T connector wires. 

 

Recheck your wiring.  Looks like you cut the plug off of the old external regulator and used it for the connecting, but I can't see the wire colors on the harness side. 

Use the write-up here,   It's for a 77.  Not having a diode won't stop charging from happening.  It's the power missing from one of your wires that is the problem.  You should have power on both with the key on.

http://atlanticz.ca/zclub/techtips/alternatorswap/index.html

[Al 77 280z]

The 2 looped wires are as followed

Solid blue 1 to white with black stripe 5

White with red stripe 2 to solid yellow 3

Edited April 6, 2016 by Al 77 280z

[Zed Head]

1 hour ago, Al 77 280z said:

tytjjrft

 

Measure voltage at the T plug with the key on.  Your L wire might not be providing power.  That would be the blue to W/B.  The yellow wire is the S(ense) wire.

Could be that the lack of power at the L wire was your original problem.  The bulb in the voltmeter can burn out and cause this problem.  Or if you don't have the gauge installed.  You can work around by using one of the other wires at the plug.  But you won't have a Charge lamp.

[Al 77 280z]

Thank you

I will have to look and see which of the T connector wires is getting voltage and which is not. Do you know what colors wire the Sense and L wire are? This way I can figure out which wire isn't getting voltage. 

I have never seen my charge lamp turn on but my gauge does work. 

[Al 77 280z]

With the key in the on position I'm getting the following readings at the T plug.

Solid yellow wire - Getting battery voltage

Yellow w/ Black stripe - No voltage

 

So according to you Zed Head my L wire is the one not getting voltage.

Edited April 7, 2016 by Al 77 280z

[Driftinrican]

Change the bulb in the volt meter. I have a friend with your setup on his 77z and that was his issue. The bulb should light up with the key on engine off. If it doesn't replace it. And if you still are having charging issues continue to follow that path.