mr2's. fires. ground potential. what you NEED to be doing to your car right now.

[ShackC]

Originally Posted by canadam

Still looking for a full list of grounds in a 3SGTE engine bay...

youll find them most easily with just some looking, i dont have a list, im sure most others dont, maybe you can make your own, and post it.

[ShackC]

There are two wires, being ground wires to my belief, they are both one on each side of the engine bay, mounting between the upper strut mounts, to the engine side covers, they make no sense if they are even supposed to connect there.

[TomsMR2]

the engine harness has brown eyeletted wires on it that are grounds as well. they kinda only reach the holes they're supposed to go to, but as long as they're secure they're in the right place. adding additional grounds from the drivertrain to the ground also helps ensure everything has equal ground potential.

[RedJaxMR2]

Originally Posted by canadam

Still looking for a full list of grounds in a 3SGTE engine bay...

There is a thead on the OC where someone has taken pictures of all the ground points. I'm at work atm can access this site but the OC is blocked otherwise I would provide a link. I'll edit this post when I get home and can track it down.

[Oteck]

try reading the electronic wiring diagram, it shows all of it

[mr2_fast4u]

good Info

[neemo6]

Anyone have any pictures as to where these grounds are located and how it should look like i plan on doing this sometime this weekend while a wait for a new alternator.

//Update//
Just took a look at some grounds that i had. In the frunk i have a cable from the negative battery post to the would be firewall. It the only ground in the frunk. In the engine bay the only one i saw/noticed was one by the strut tower to the engine side cover, it really doesnt seem to be grounding or doing anything. Not sure if the PO didnt know where it was supposed to go so he just put it to where it reaches. Is this right?

[neemo6]

Here are the only grounds I see on my car.

Frunk


Engine bay

[Starlet 3SGTE]

Didn't read all three pages as my internet is dragging horribly however a few small details on the initial write up. I'd use a 4awg wire in the frunk even for the extra ground, and make sure the battery terminals are in good shape, clean and tight. You'd be shocked how many cars per day come into my shop with corrosion so thick you can't even see the shape of the terminal. Others are so rotted you wonder what holds it on the battery.

[neemo6]

So I need 2 grounds from the battery? Any idea, as to what that ground in the engine bay is supposed to be going?

[Benckj]

I've been preaching the good ground practice for years. It's amazing how many people don't check or look after this critical circuit when the results are devestating. Just a couple of points I'd like to add to the above comments;

> Don't just check the tranny<>chassis ground. Completely remove it and clean both ends including threaded bolt holes. Re-install using some conductive grease like copper coat. It's the threads in the alloy casting of the tranny which generally causes problems due to the junction of two metals and exposuirew to enviromental conditions.

> Add a fire blanket to the list of things to carry. These are very useful in smothering a fire and can be used on people as well. They are very cheap (<$10), never wear out or expire and are so small they can be thrown in the glove box. Great to have one in the kitchen as well.

> I might be breaking some protocol but here is a link in the other forum on ground points. Great pics and descriptions where they are. MR2 Owners Club Message Board. If I'm breaking some rules the the Mod can just delete and give me a slap on the hand but if I help one person it is worth it.

jimb

[neemo6]

That link takes me to a forum with no posts. Someone on this board has to have pix of their grounds. Anyone?

[bear3104]

Im a car noob, but going to try and start learning. I actually had a friend in high school who's sw20 burned to the ground. It was so sad.

Is this a problem in AW11's? if so could someone post pics please of the ground points (so i can show my mechanic, im a noob remember). I will be getting an AW11 soon, but I dont want to die in a fire lol.

[goopi]

Originally Posted by bear3104

Im a car noob, but going to try and start learning. I actually had a friend in high school who's sw20 burned to the ground. It was so sad.

Is this a problem in AW11's? if so could someone post pics please of the ground points (so i can show my mechanic, im a noob remember). I will be getting an AW11 soon, but I dont want to die in a fire lol.

Upgrading grounds in all cars should be considered, it makes quiet a difference from my experience.

Its just the fact that some cars have good grounds set from factory and some don't (like the mr2), over time they also corrode and sometimes they're even missing.

[neemo6]

Originally Posted by bear3104

Im a car noob, but going to try and start learning. I actually had a friend in high school who's sw20 burned to the ground. It was so sad.

Is this a problem in AW11's? if so could someone post pics please of the ground points (so i can show my mechanic, im a noob remember). I will be getting an AW11 soon, but I dont want to die in a fire lol.

Good luck trying to get someone to post pix, I've been trying to get this help since I got my mkii. if you join the other mr2 board there is a great thread with pix. There is a link couple posts up.

[TomsMR2]

to find the ground "points" you only need to read the thread and understand it.

its kinda like asking where the ground point in your lawn is. its all the ground. thats why its called that

the mr2 has really pretty good grounds from the factory. the harness is very well laid out. the problem is that after ~20 years, people tend to leave them undone, or loose, or the harness just corrodes. adding in the suggested grounds clears any of these potential problems. a ground is a ground is a ground.

[bear3104]

Well i dont have my AW11 yet so i cant go look at one. I was just hoping for someone to just post a couple quick pics of where they are. I'm a total noob. Hopefully by the time I get it someone will have posted pics

From your view its easy, cuz well u know alot about cars. But from my view im totally lost cuz anything more than an oil or tire change is above my head right now. But I want to start learning.

It's hard to learn when people aren't willing to help a noob out though haha.

[TomsMR2]

follow the thread, we'll help if you'll take the help

the entire chassis is the ground. thats why you need to ground the battery properly to it. theres a factory ground wire which should be cleaned up. I suggest adding another ground from the battery to the chassis.

the engine itself needs to be grounded. theres a ground strap from the transmission to the chassis. you should clean that, and add another ground from the transmission or engine to the chassis. it doesnt matter where it goes, as long as its on a clean spot on the engine, and clean spot on the transmission.

those two, and solely those two, will prevent mr2 fires. automotive electric isnt the easiest thing to understand, but im trying to get people to grasp the basic concept of what a ground is.. which is the entire chassis. you cant think about a ground as a specific point that a specific wire needs to attach to.

if it needs to be grounded, it needs to somehow touch the chassis, ideally with as short a wire as possible. the factory ground points are where they are because thats whats convenient for the harness to reach.

[bear3104]

That made alot more sense thanks

I understnad what grounding is basically. I was just asking where the factory ground points were on an AW11 so I could have a friend or my mechanic show/help me when I get the car. I get that the factory points are convienient, which is why I was asking for them. This is something that I'm gona have help on for sure, so attaching the grounds on non factory places is not something Im going to try and do. At least at first. Although it makes sense of course.

I mean I get the purpose of groudning. At the place I work the factory workers have to wear ground straps on their shoes so they dont ruin the computer boards they work on by zapping them with static etc. I just have no experience working on cars at all. Hopefully that will change in time.

[gregman_1]

Originally Posted by bear3104

That made alot more sense thanks

I understnad what grounding is basically. I was just asking where the factory ground points were on an AW11 so I could have a friend or my mechanic show/help me when I get the car. I get that the factory points are convienient, which is why I was asking for them. This is something that I'm gona have help on for sure, so attaching the grounds on non factory places is not something Im going to try and do. At least at first. Although it makes sense of course.

I mean I get the purpose of groudning. At the place I work the factory workers have to wear ground straps on their shoes so they dont ruin the computer boards they work on by zapping them with static etc. I just have no experience working on cars at all. Hopefully that will change in time.

Nice thing about grounds is that they're easy to find.

Look for wires that connect directly to the chassis or body with a bolt. These will come from the battery, the fuse boxes, the engine and/or transmission. Those are your grounds. They need a good, clean connection at both ends. Take the bolts out that connect them to the chassis and/or engine/transmission and clean them with a wire brush. Make sure there is a spot of bare metal underneath the wire terminal anywhere a ground wire attaches to a painted surface. If there's not, take the bolt out and hit it with some sandpaper until there is.

ANYWHERE you have dissimilar metals in contact (aluminum transmission with a steel bolt for instance), you will have a process called galvanic corrosion. This effect is compounded 100x by electrical current (i.e. a ground strap). As benckj stated earlier, something like copper coat grease is EXCELLENT at helping to prevent this galvanic corrosion. Just make sure you use a CONDUCTIVE grease.

If you are going to replace or augment a ground wire or ground strap, use the same or (preferably) larger gauge wire than what came off and heavy duty, well-crimped ring terminals on both ends.

The nice thing about grounds is that you can't overdo it. You could add ground straps until you're blue in the face and all you'd get is a safer, better-running car. Of course, at some point you're wasting your time, but you certainly won't hurt anything.