Alternator Issues

[ksechler]

I need some help with my internally regulated alternator.  

I have a 1976 280z that I have been restoring (full rotisserie resto-mod).  The car is pretty complete mechanically.  I have removed the fuel injection and fuel injector harness and control.  I have removed the distributor and transistor ignition module.  In their place I have triple OER Carbs and an XDI electronic ignition.  I don't that either mod bears on my present problem.

I have installed a 60a internally regulated alternator.  I performed the wiring modifications shown here:

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

The problem is that it doesn't seem to work.  I can start the car, but the red charge light is on and the voltage shows less than 12V on the gauge and using a multimeter.  I noticed something else suspicious.  When I jumper the 2/3 wires as shown in the article I linked, I can hear a relay pulling in (probably the ignition relay but I'm not sure) without the key being in.  This doesn't seem right at all.  

I removed the jumpers and If I connect a lead directly from the battery to the "F" terminal then I can get 12.5-13V, but my charge light wont work.  Can anyone lend any insight?  First of all what voltage should I see off a properly charging IC alternator?  How should I check it?  Why do I hear that relay pulling in when jumpering the plug?  Also there was a small canister (diode or a capacitor of something) on my old alternator.  The wire is broken.  Do I still need it with an IC alternator?  

 

[Zed Head]

"F" terminal on the alternator?  Internally regulated alternators don't have an F.  They have an L.  Maybe you got the wrong alternator.

76 also has the brake warning lamp check relay wired in to the regulator circuit.  It's not addressed in the atlanticz writeup,which he wrote for a 77.  It's on here somewhere, I wrote about it years ago.

[ksechler]

36 minutes ago, Zed Head said:

"F" terminal on the alternator?  Internally regulated alternators don't have an F.  They have an L.  Maybe you got the wrong alternator.

76 also has the brake warning lamp check relay wired in to the regulator circuit.  It's not addressed in the atlanticz writeup,which he wrote for a 77.  It's on here somewhere, I wrote about it years ago.

No, It is internally regulated.  I was talking about the location corresponding to the original "F" terminal.  The vertical connection on the two wire "T" connector.

[Zed Head]

That would be "L".  There might even be an L molded in to the case.  The atlanticz method should work fine, but it will leave that relay powered with the key off.  

12.5-13.0 volts isn't enough info and engine RPM is important.  All of the Z and ZX alternators are low on output at low engine RPM.  You need to raise RPM and see if voltage increases to ~13.8 - 14.4 (around there) volts.  If your battery is weak it will suck up the current at low RPM also.  So if you did the wiring yesterday and the relay was activated overnight your battery is depleted.  You can unplug the brake check relay with no problems.  

The charge light won't work when you remove the jumpers because that's where the power source for the charge light is. Edit - actually it might not be the source, just the ground circuit.  Either way, you need the jumpers.

Anyway, you might rejumper it and measure voltage at higher RPM.

Edited August 15, 2016 by Zed Head

[ksechler]

47 minutes ago, Zed Head said:

That would be "L".  There might even be an L molded in to the case.  The atlanticz method should work fine, but it will leave that relay powered with the key off.  

12.5-13.0 volts isn't enough info and engine RPM is important.  All of the Z and ZX alternators are low on output at low engine RPM.  You need to raise RPM and see if voltage increases to ~13.8 - 14.4 (around there) volts.  If your battery is weak it will suck up the current at low RPM also.  So if you did the wiring yesterday and the relay was activated overnight your battery is depleted.  You can unplug the brake check relay with no problems.  

The charge light won't work when you remove the jumpers because that's where the power source for the charge light is. Edit - actually it might not be the source, just the ground circuit.  Either way, you need the jumpers.

Anyway, you might rejumper it and measure voltage at higher RPM.

I measured voltage at high rpm.  I never got better than 12.7.  I can't tell you exactly how high because my tach doesn't work yet.  Something isn't right.  I suspect there is a short somewhere.

[siteunseen]

If it's a reman from a chain store it could be faulty.  Happened to me a few months ago.  Took it back and had it tested, FAILED, they overnighted another one and I had them test before I left the building.  It PASSED and shows 13.75 at 900 RPM with nothing on but the spark plugs. 

[Zed Head]

To be sure - did you connect L to the positive side of the battery?  Is it a new or rebuilt alternator or used?  Are you sure that it's in good shape?  Have you confirmed that the alternator case has a good gorund circuit to the negative post of the battery?

Power to L should have caused charging, even higher than 14+ volts because you didn't have "S" connected.

I would get the meter out and check grounds and power sources.  Make sure that everything that is supposed to be there is actually there, power and ground-wise.

[Chickenman]

Atlantic Z car site seems to be down. Z car creations has some good info as well, including proper connections on rear of LR160 alternator. BTW... make sure that you do have an LR160 alternator ( IR )  and not an LT160 alternator ( ER);

http://www.zcarcreations.com/technical/lr160term.htm

 

On back of Alternator: Top horizontal connection of the Terminal is your " S " or Sense signal. Also called N or Ign on some alternators Should be a Yellow wire on 280Z.

Vertical connection is your " L " or Lamp signal. Also called " F " or Field on some alternators.

 

 

[Zed Head]

It's called F and N on externally regulated alternators.  L and S on internally regulated.  Diagrammed out with good illustration in the 1982 280ZX Electrical chapter.  You're repeating already stated facts.  Might read through previous posts first, it will keep things clearer.

The zcarcreations wiring scheme screws up the proper operation of the Brake light in the dash.  It's different from the atlanticz scheme.

[Chickenman]

Not repeating already stated facts.  In fact I'm trying to correct some misconceptions.  As far as N = S and F = L . Internal or external regulator does not matter. That is an industry standard taken from alternator rebuilders.

Z Car creations does not screw up the proper operation of the Dash light. It does it correctly by going through the charge lamp for a 1976 2880Z's .

I just did the swap from an External Regulated 60 amp 1976 280z alternator  to a 1985 300ZX IR 70amp alternator. I specifically used the Z car creations article because it takes it uses #1 lead to connect to #5 ( #1 Lead is Ignition switched source that goes through the Charge Lamp ) That is the CORRECT way... for a 1976 280Z.  Which is what OP has. 

Atlantic Z uses a constant 12 V source for the pairing to #5.  I can't remember which one and their site is down. It will probably work as well, but not sure if Charge light will go out on a 1976 280Z. I wasn't taking a chance.  And it leaves the constant battery connection to the circuit which leaves a minor draw on the system. Not a lot.. but it can drain the battery. This is all documented if you research enough. BTW... a 1982 280ZX wiring diagram is not really relevant to a 1976 wiring diagram is it. 

Bottom line is the Z car Creations site for 280Z cars is in fact correct.  I just did the swap. Viewed from the engine harness side ( Important little step ) you connect #1 and #5. and #3 and #6. Charge and Brake lamp work perfect. I get a solid 14.3 volts at idle ( 1,000 ) RPM and 14.54 volts at 2,000 rpm.

From Z creations site:

Wiring With the old VR connector plugged into the engine harness connector, there are six different wires:

Connector Position	WIRE COLOR	New Connection	WHERE IT LEADS (Refer to PicC)
1	white/red	connect to 5	goes through the charge lamp in the dash to a +12V ignition source at the fuse box
2	white	NOT USED	battery connection - constant +12V
3	yellow	connect to 6	goes to "S" connector on alternator
4	black	NOT USED	goes to "E" on alternator - ground
5	white/black	Connect to 1	goes to "L" connector on alternator
6	white/blue	Connect to 3	a true +12V ignition source

That is it. The charge light will work correctly and the remaining two wires (white and black) are unconnected and unused. Enjoy.

 

[Zed Head]

Does the "Brake" light light up when the key is On, but engine not running?  If it doesn't the Check Relay is not checking. 

I have a 76 and I've tried all of the schemes and fixed the problem with the atlanticz scheme.  I just did the swap about five years ago.

 

Etiquette.

Edited August 15, 2016 by Zed Head
Cleaned up a wizz puddle

[ksechler]

Guys:

First let me thank you for the replies.  I wasn't trying to start a war.  I got the alternator working last night.  My experience was that the Z Car Creations wiring does work, but the Atlantic Z Car Club does not work.  They both connect the #1 and #5 wires, but the Z Car Creations swap connects #3 to #6 while the Atlantic Z Car Club connects #2 to #3.  I don't know if there is variation year-to-year.  For what it's worth my car is a 1976.