Getting ready for more electrical updates on some of the projects and have been checking out the MAD electrical website along with various other sites before I do some upgrades.

Looking at some pros and possible cons of the relay system for headlights,heater blower motor and any other future modifications.I have relayed the headlights on a few different vehicles now and am impressed with the results but wonder that since the amp load/current draw has now been removed from the main wiring harness where the voltage regulator receives its signal from, does this now mean that the regulator does not "see" the load and therefore will not increase the alternator output to account for it?

What if we hook up all sorts of relays for multiple heavy load drawing accessories off the alternator output stud? Does using relays affect or bypass the correct signal the voltage regulator needs to control alternator output?

Also where would be the best location to install the voltage regulator lead...at the very end of the line of all electrical draw would make the most sense,but since it would be completely impractical to have a voltage sensing wire at the end of every electrical item on the car and have them all work at the same time...would the next best loction be before the main junction that supplies everything...the fuse box? Is there even enough of a drop in voltage to worry about it?

I'm probably making it much more complicated than what it really should be but I am running all new charging wires on a '66 Chrysler...losing the mechanical regulator for a solid state...bypassing the amp gauge...and installing a 78amp alternator...relaying headlights and heater blower motor...and will have plenty of other electrical upgrades as well at some point I'm sure.Just wondering if I'm trying to over-engineer the issue. Thanks...

simply put, the battery is the supplyer of voltage for everything.
regardless of where you tap off power, it all ultimatly comes from one source.

when you pull it further from the battery, you get other losses that cause the sensing voltage to drop based on losses.

So to prevent over charging, you run it as close to battery voltage as possible.

typically, I run a relay for sensing voltage, so it comes directly from the battery.

It's nice to get a lot of the headlight amperage out of the headlight switch/ bulkhead connector, but I question the need for a relay for a stock heater blower motor.

Using the alternator output lug, while handy, does bring additional wiring into a relatively tight/ hot area.

It's my undertanding from the Mad Electric Guru's writings that it is the alternator that provides the dominant source of power to your system. The battery is there to start the car etc. If you wire your system to take advantage of this fact, your electrical system will be more efficiently able to distribute the main source of power from the alternator to the items that need it, including the battery.

Mad Electric covers remote voltage sensing and the proper location for the "sensing" wire. He runs his over to the battery +. I ran mine to the distribution lug I installed under the hood, as that is where most of my main amp loads are fed.

You only need one sensing wire, but some places in the system are better places than others to put it. That is why remote sensing wire systems are better than single wire alternator systems. A single wire system senses voltage inside the alternator.

I chose to use Mad's distribution lug concept, feeding the distribution lug with a fused cable from the alternator to lug which I placed near the factory starter relay.

Because my fuel pump is downstream and relatively far away from where the rest of my high amp loads are being distributed, consequently the load it puts on my system is not sensed as efficiently, because my sensing wire is sensing voltage at a less than optimal spot. While it still works very well the way it is, it's not the best place because such a high amp load is taxing my circuit so far away from the sensing wire location. I believe relocating the sensing wire to my trunk mounted battery will buffer the slight variation in voltage I see/hear as the regulator tries to adjust alternator output to match my amp draw under the hood.

I'm still learning this stuff too, and a mistake I believe I made is that I wired the sensing wire up front at my distribution lug. Since my battery is in the trunk, as is my fuel pump which is fed by 2 fused 40 amp relays; watching the volt gauge and listening to my fuel pump, I can hear the sound of the fuel pump change and see a slight wavering of voltage when the fuel pump goes through it's various electrical loads. For that reason, I may move my voltage sensing wire to the battery/ trunk to better account for the fuel pump's draw