- D -

Defogger

That part of the heater system designed to clear the windshield of fog haze under certain conditions.

Defrost Door

A small door within the duct system that diverts a portion of the delivery air to the windshield.

Defrost Switch

A thermostatic-type switch that senses evaporator temperature and turns the compressor off to prevent frosting or ice formation on the evaporator.

Defroster

That part of the heater system designed to clear heavy frost or light ice from the inside or outside of the windshield.

Defroster Door

A term often used for defrost door.

Deg

An abbreviation for degree.

Degreaser

A chemical that breaks oil and grease down.

Degreasing

Cleaning parts in a solvent to remove oil and grease.

Degree

Part of a circle; one degree is 1/360th of a circle.

Degreeing A Cam

Using instruments to determine the actual timing of valves opening and closing for a particular camshaft.

Dehumidify

To remove water vapor from the air.

Dehydrate

A process for dehumidifying.

Dehydrator

1. A machine used to dehydrate a system or component. 2. A term often used for drier.

Dehydrator Filter

A term used for filter drier.

Deka

The prefix representing the number 10.

Delayed Time Base

A time base with a sweep that can start (or be triggered to start) relative to a pre-determined time on the main time bade sweep. Allows the user to see events more clearly and to see events that are not visible solely with the main time base sweep.

Delco Eye

A type of built-in battery tester that provides an immediate visual indication of battery conditions.

Delta "p"

A term used when referring to a difference in pressure.

Delta "t"

A term used when referring to a difference in temperature.

Delta Connection

The interconnection of three windings, such as an alternator stator in a triangular fashion. Named for the triangle shaped Greek capital letter delta, also known as a delta winding.