shadetree
New Member
- Joined
- Sep 9, 2007
- Messages
- 1,794
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- Age
- 84
- Location
- East Texas
- Vehicle Year
- 1994
- Make / Model
- Explorer Sport
- Engine Size
- 4.0
- Transmission
- Automatic
What is ground? In the automobile application, it is a 0 voltage reference point, or a return path for current, or both. The engine is is most always at battery ground if wired properly.
Current/voltage has to come from somewhere, it cannot be generated from thin air without some type of device to do so. The vehicle has a battery to supply electrical power. The battery will have a positive connection and a negative connection. The negative connection in most modern applications is considered as ground. In early automotive designs, the positive terminal was used as ground.
The spark plugs are screwed into the engine block which is at ground potential, and the plug centers are attached to the ignition coil secondary wiring in a series circuit configuration. Although, the coil secondary in the dis/edis system is not physically connected to the block directly, the current path does go thru the sparkplug to engine ground completing the current path.
The attached diagram is from "How to Understand, Service, and Modify Ford Fuel Injection & Electronic Engine Control," by Dr. Charles O. Probst, SAE, page 125. Who is Dr. Probst?
http://www.bentleypublishers.com/author.htm?who=Charles_O._Probst,_SAE
It shows how grounding is achieved in this configuration. The engine block is the return path for current, hence, ground.
Those who are interested, and kinda understand electrical circuits can determine from themselves whether or not there is a ground.
Current/voltage has to come from somewhere, it cannot be generated from thin air without some type of device to do so. The vehicle has a battery to supply electrical power. The battery will have a positive connection and a negative connection. The negative connection in most modern applications is considered as ground. In early automotive designs, the positive terminal was used as ground.
The spark plugs are screwed into the engine block which is at ground potential, and the plug centers are attached to the ignition coil secondary wiring in a series circuit configuration. Although, the coil secondary in the dis/edis system is not physically connected to the block directly, the current path does go thru the sparkplug to engine ground completing the current path.
The attached diagram is from "How to Understand, Service, and Modify Ford Fuel Injection & Electronic Engine Control," by Dr. Charles O. Probst, SAE, page 125. Who is Dr. Probst?
http://www.bentleypublishers.com/author.htm?who=Charles_O._Probst,_SAE
It shows how grounding is achieved in this configuration. The engine block is the return path for current, hence, ground.
Those who are interested, and kinda understand electrical circuits can determine from themselves whether or not there is a ground.
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