[vex]

Complete sentences helps illustrate your point much better than half-assing. Just sayin'.

Originally Posted by FRED

I see no reason you won't still have the CPU 'cause it is tied to the turn signals etc and it's not part of the EM harness on the engine. So if you keep that CPU that means the alternaor relay is still active inside the CPU and all you have to do is run a wire/splice a wire to the white/black wire at the CPU plug to the alternators small connector to have normal alternator excitation.

With a haltech etc your losing the EM harness that the white/black normally runs thru on a NON TURBO car and that's why you'd run a new spliced wire from the CPU's white/black to the alternators small plug. IF the car is a TURBO car the white/black does NOT run thru the EM harness on the engine but thru the harness on the left side of the engine (that's the engine harness) . That's shown in the first jpg I attached.

The car itself is non-turbo (at least it was until I decided I was turbo charging it). Which means that the Alternator Wires pass through the EMS harness. Thus the reason for this thread. Unless the computer does something to the initial excitation voltage that I'm unaware of I do not see any benefit in keeping the warning system (IE passing the voltage through the warning light relay). Since the internal structure of the alternator dictates when the charging warning light comes on or off based on the voltage of the switched 12v source matching or exceeding the initial excitation voltage I see no reason not to bridge both the Black/White and White/Black wires (the warning system is being replaced by the digital dash and stand-alone EMS). Since the voltage coming from the black/white wire will meet or exceed the initial excitation circuit, the function of the Alternator will not be impeded. That's all I needed to know. If however I'm reading the information wrong, help me understand.

Originally Posted by FRED

About the SELF EXCITATION............what I mean is that there is residual magnatism in the rotor of the alternator and if you spin that sucker up high and fast that that residual magnatism will cause the alternator to self excite and put out. I don't recommend leaving the white/black off, just saying that a series four will put out without the white/black excitation wire being hot.

Some people say that you can run switched voltage to the white/black wires contact on the alt and things will be fine. I differ a bit on that .

Again.........whether or not the alt relay ever pulls in or not matters not. As long as the METER fuse (or other switched power fuse power) goes thru the COIL of the alt relay to the alt is what matters. It is INDEED looking for a ground to cause the alt relay to pull in and tell the driver the alt is not working.........but that is NOT the main reasone they have power going thru the white/black to the alternators field. It going there to excite the alternator so it'll put out.

Ah heck. Run a switched power to the white/black and have at it. The alternator will put out...........but if it were me........I'd run a wire from the white/black at the CPU plug to the alernator and make the system as factory designed. I mean you NEED the CPU anyway.

This a turbo or non turbo car??????????

Why? You stated you wouldn't do it this way, but why?

Originally Posted by FRED

Your misunderstanding me.......................the excitation power comes from the METER fuse. That power travels thru the COIL of the Alternator relay NOT thru the contacts of the alternator relay.

So now you have the alt relay in the CPU getting power on its plus side of that coil. The negative side of that alt relay coil now travels on to and thru the alternator regulator and finds ground in the alternator itself.

So the alt relay now has power on it and a ground so it pulls in and caused the Warning lights to come on on the dash.

Now you start the engine and the alternator puts out. Now what was/is the ground wire of the alternator relay has power on it that more/less matches the plus side of the alt coil so that causes the relay to relax and break the contacts that go to the warning unit which in turn makes them go out.

The warning light unit itself has zip to do with the excitation of the alternator.It's the Meter power passing thru the COIL of the alt relay that IS the excitation power for the alternator. Normally if you backprobe the White/Black wire with the connector connected to the alt and key ON........the voltage reading will not be batt votlage but approx 3vdc (bit of a voltage drop there from the batt voltage entering the alt relays coil).

I wrote too much this time.

Alright, this doesn't make any sense to me. Are you stating that it takes only 3vDC to initiate the initial excitation of the coils (I'm not talking about the warning relay), or are you saying that the initial excitation voltage experiences a 3vDC drop (so instead of a 12.0v it sees a 9.0v).

Originally Posted by FRED

*(Ahhh, I see. So the initial excitation does occur via the relay. Does the relay circuit break after 12V excitation occurs? And is there any ill effects from bridging both the white/black and black/white wires to a 12v switched source?***

I'm going to beat this to death...................remember, its power passing thru the COIL of the relay NOT power passing thru the alt relays contacts that excites the alternators field.

The alt relays CONTACTS are harmless things that do nothing more than put a gnd on the Warning lights to make them all come on and nothing more. Ignore the contacts of the relay and pay attention to the Coil of the alt relay and power passing thru the coil to the alt itself. Gone for now.

I understand that. I was talking about the original circuit and keeping the alternator charging light off, while still being able to have a functioning alternator. As stated earlier the warning system will be superseded by the EMS warning system.