Tech Tips
Basic Auto Electrics

Sooner or later you've gotta' dive into some wiring. The new mod, the new stereo, the new alarm. It can be pretty confusing and an improper understanding of some basic Auto Electric Principles can be downright dangerous for your cars health not to mention your pocketbook.

As this page starts I will be using my own understandings and wordings and as time goes by I'm sure I will be corrected by those in the profession. Which I welcome.....but for now.

AC/DC ~ (Not the Band)

AC ~ Alternating Current ~ All things electric need a positive and negative source to operate. AC voltage alternates between positive and negative to meet this criteria. Commonly using 3 conductors, a ground, a hot wire, a neutral. The hot wire and the neutral are the ones that will zap you and are the ones you remember on the old plugs that just had two connectors before the 3-prong thing. And yes there is a proper way to use the hot and neutral, and yes it will work if you reverse them, and yes, it will be "out of phase" if you reverse them.Primarily your household wiring. Not to be dealt with right here right now. As long as your drill works, your sander operates, your AC is fine.

DC ~ Direct Current ~ This would be your car, more precisely your car battery. Utilizing a positive pole (+) and a negative pole (-) aka Ground.

Amp ~ Amperage ~

Volt ~ Voltage ~

Switch ~
Engages a choice in most cases on/off. Also either route A or B. Also available in two way (on/off) or three way (off/up/down) or (off/A/B) however you see it.

Normally Open ~ When a switch or relay in it's natural state is breaking contact for you.

Normally Closed ~ When a switch or relay in it's natural state is making contact for you.

These terms apply to switches or relays (which is a switch)

SPST ~ Single Pole/Single Throw ~ Controls one device with one function. (2 choices On or Off)

SPDT ~ Single Pole/Double Throw ~
Controls one device with two functions. (3 choices, A, B, or Off)

DPST ~ Double Pole/Single Throw ~
Controls two devices with one function. (2 choices, On or Off)

DPDT ~ Double Pole/Double Throw ~
Controls two devices with two functions. (3 choices, A, B, or Off)

Relay ~
A relay is a heavy duty electro-magnetic switch. When you have a hi-amp circuit to switch on or off due to the amount of current involved it is smart to use a relay. By applying a lo-amp current from a switch or sensor the electro-magnetic plunger either sucks down or up to control a heavier set of contacts containing hi-amp current. This is a safety valve in that should trouble arise in the hi-amp circuit it is safer to blow a relay than a motor and because of the containment of the relay any contact arcing or sparking is more so contained. Basically ~ less fires this way decreasing the load on your basic wiring system.

Hi-Amp ~
For many of my illustrations and examples I use this term to represent a high current flow. It's still 12 volt, just draws a lot of current. Example: Fan Motor, Power Windows, Starter, Door Locks, Power Seats, horn, heater fan, head lights.

Lo-Amp ~
For example radio, dash lights, dome lights, etc.


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