Lets Talk about Grounds

[86yota]

I was told my a good mechanic that grounds are very important in how your car Runs. But i never really got into replacing any of mine. Now iam just trying to Figure out what is the best wire to use something thicker i would guess. 12g ?10g?, But whats the best type to use for grounds. Also i was told the more you have the better you are protected where would be good places for more grounds. ? My car is a 86.5 w/ a 87 rebuild 7mge.

 

[suprahero]

I have one on the back of my head, my exhaust manifold, my starter, my battery and I think that's it. I'm not saying that those are the best places, it's just where I have mine. They are important though. I also have one going to one of my coilpacks.

 

[Justin]

I replaced every factory ground wire in the engine bay with some quality 4ga copper wire commonly used in amplifier installs.

 

[86yota]

I have one on the back of my head, my exhaust manifold, my starter, my battery and I think that's it. I'm not saying that those are the best places, it's just where I have mine. They are important though. I also have one going to one of my coilpacks.

Cool I guess ill just replace mine with 4g or 6g depending on what is goingfrom, i as long as is grounded to the body it should be ok

 

[CRE]

Some people like to REALLY go overboard. I haven't quite gone to these lengths but this is a commonly recommended scheme:

Connect a ground block directly to the (-) battery terminal with as short of wire as possible. Use 2AWG or better. From the ground block run 4AWG wire to: Block, Head, Intake Plenum, Chassis (in the front and rear), Igniter shell, ECU shell, Transmission and some even recommend grounding the radiator...

I've got about half of that grounded. Really, replacing the factory grounds with copper wire of the same gauge or better is sufficient for most older vehicles.

 

[suprarx7nut]

Some people like to REALLY go overboard. I haven't quite gone to these lengths but this is a commonly recommended scheme:

Connect a ground block directly to the (-) battery terminal with as short of wire as possible. Use 2AWG or better. From the ground block run 4AWG wire to: Block, Head, Intake Plenum, Chassis (in the front and rear), Igniter shell, ECU shell, Transmission and some even recommend grounding the radiator...

I've got about half of that grounded. Really, replacing the factory grounds with copper wire of the same gauge or better is sufficient for most older vehicles.

Say what? Did you mean "from the grounded block run wire to: Head, ...etc."?





**EDIT!!! <<<<HOLY SHIT, POST #1000!!! It's the small thigns in life, I tell ya...

 

[CRE]

Say what? Did you mean "from the grounded block run wire to: Head, ...etc."?

Yup.

**EDIT!!! <<<<HOLY SHIT, POST #1000!!! It's the small things in life, I tell ya...

Excellent! We'll have a party, I'll let you work on my car and I'll make hamburgers while you get dirty... it is after all the small things... think about it, burgers you won't even have to cook.

 

[figgie]

Well here is some food for thought.

Grounding points on the supra are all over the place. There are tons and tons of points as evident here.

http://www.cygnusx1.net/Supra/Library/TEWD/MK3/manual.aspx?S=Main&P=26
http://www.cygnusx1.net/Supra/Library/TEWD/MK3/manual.aspx?S=Main&P=28
http://www.cygnusx1.net/Supra/Library/TEWD/MK3/manual.aspx?S=Main&P=30

http://www.cygnusx1.net/Supra/Library/TEWD/MK3/manual.aspx?S=Main&P=148
http://www.cygnusx1.net/Supra/Library/TEWD/MK3/manual.aspx?S=Main&P=149
http://www.cygnusx1.net/Supra/Library/TEWD/MK3/manual.aspx?S=Main&P=150

I will tell you this. The point that would concern me more would be anything that uses the body as the common ground that is furthest away from the battery.

Corrosion, galvanization or lose welds make for very poor electrical conducting paths.

 

[jetjock]

The vehicle already has redundant grounds in every circuit but one. Therefore a "more is better" approach is electrically stupid, as is (generally speaking) increasing the size of grounding conductors. Most grounding problems are owner induced anyway. They do things like reuse the special grounding bolts Toyota put in the car, use a normal bolt, employ inferior types of connections, and fail to run new grounds to one of stock grounding points.

A near perfect grounding scheme is to replace the block, battery, firewall and engine to transmission grounds. Also add an igniter ground and chain it to the ECU and fender ground. Then analyze which of the redundant stock ground points are closest to the battery and chain them together with a single 10 AWG, ending at the new battery negative point on the left fender. Use new grounding bolts when doing it. When finished load and voltage drop test the chain from the battery negative to the center hatch ground, which is the furthest stock point. Correct any point that measures more than 100 mv. There shouldn't be any if you did things right. Finally, any future grounds added should go to the closest ground point, never to the chassis.

The process is not all that difficult to do and will completely remove any circuit's dependence on the chassis for grounding, while leaving it as a back up.

 

[86yota]

Sweet thanks for sharing some knowledge about this i know have a better understanding of what i need to it.