No harm, besides maybe driving around with your parking brake on.  I've generally thought that its other function, of showing a brake pressure imbalance, was kind of worthless.  It shows up in the brake pedal anyway.

Edited March 6, 20169 yr by Zed Head
its not it's

Note that the below has been edited to fix incorrect information:

 

Depending on the year, they changed the way that "brake warning lamp check relay" is implemented, but all the brake warning relay does is 1) test the functionality of the brake warning bulb in the speedo before the engine is started, and 2) and warn you that you have lost power brake vacuum in the event that the engine has stalled.

 

Your brake lamp will still light up just fine when you pull the emergency brake, and it will also still light up if the hydraulic brake indicator switch detects a fault in the braking system.

 

All they were trying to do with that relay is provide you with a short term temporary "lamp test" mode that would allow you to verify that the warning indicators actually worked if necessary and warn you if you lost power brakes. I disconnected mine a while ago, and since I always pull the E-brake when I park, my bulb gets tested for functionality every time I pull the handle.

 

As for your alternator connections, you're OK with that now, right?

Edited March 7, 20169 yr by Captain Obvious

I disconnected my '77's under the passenger's seat.  Works when the E-brake is pulled only, like The Good Captain says.

This is why we don't past after midnight.  Captain's right, it's just a bulb check relay.  I'm usually the one that rights out all the words for that thing too...

For a small function, it has a lot of design effort in it, and can cause fairly significant problems.  It's a weird little sub-system.

Just thought of the other function of that light, the one that I've mainly used it for - ignition switch is on.  Or - what happened?  Oh, the light's on, the engine must have quit.

Incorrect details removed.

Edited March 7, 20169 yr by Captain Obvious

The light goes on when the key is turned On, right?  That's the "check" function.  Then when the engine starts, it goes off.  Pretty sure that's the same for all of them.  Otherwise the light stays on all the time, or it never "checks"..  So, key on/engine running = no light, key on/engine stopped = light.  Multi-function.

Maybe you're saying that 77 gets its brake check warning lamp relay power from somewhere else?  I was just commenting on the function of the light.  I powered my light from the fuel pump power so I have the original function plus my bonus function.  

33 minutes ago, Captain Obvious said:

The 77 doesn't do that.  That's what I meant about them changing stuff from year to year. 76 has that link between the alternator and the warning lamp, but 77 doesn't. New for 77... Other than the tach, here is no dashboard indication if the engine is running or not. It's a new feature for 77. 

Reread your post here and I think the incongruence is on the intent or the description of the intent by Nissan.  Whether they intended it to show that the engine is running with the key on, or not, it does do that.  As long as the brake lever is down.  If the engine is running and it dies on you, the red brake light catches your eye pretty quickly.

Alright, back to The Swede's issue.  The alternator swap.

Sorry, I'm not on my full keyboard, so I'm trying to type as few words as I can. 

You're right and I've removed the incorrect info to prevent confusion for people reading this in the future.

And you're right again... We're off target at this point.  Alternator it is.

Edited March 7, 20169 yr by Captain Obvious

Maaaann, I thought I was learning something new but now I don't know.  You know I love a puzzle so I went to the Owner's Manual, and found the section.  In both 77 and 78.  Copied 78 here.  They even describe it like I do, by my "bonus" function.  They mention the seat belt buzzer and timer.  Not trying to one-up, just curious.  Maybe your wires are crossed (in the car, not your head).

Sorry Swede,  This may actually be useful in the end when you get in to the swap.  If you get done and your relay is still whining, we'll know more about what to do for it.  Maybe it's actually your seat belt buzzer whining. 

Alright gentlemen, this what I've managed to get done today.

Old vs New

I still don't see the need for cutting the wiring harness to compensate for the new alt w/ its internal regulator. I jumped the wires like this, instead. No harm done to the harness, if I ever need to go back.

I disconnected the brake check relay. If the E-Brake is on, then the light is displayed on the "ON" position. If the E-Brake is off, then it doesn't. Otherwise works as normal.

Had to adjust my idle speed just a tad because with the headlights on, the car idles really rough (around 700-800RPM) and takes strange dives. With lights off, it idles at 1050-1100. My guess is that the wonderful bulbs they used back in the 70's probably weren't too keen on sharing and hog a lot of juice. Anyone experience anything different with different bulbs?

By the way, just wanted to throw another "Thank You" for all you who are helping me out with this build. I am extremely grateful. 

Not sure if I ever shared this, but this was how the stock EFI L28 sounded.

 

The exhaust I have on for this new motor is a temporary magnaflow. Way too aggressive for my taste, to be honest. When it comes to these sports cars, I prefer the purr over the growl. Just my preference.