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My fix for a ground cable to the engine

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Old 10-04-2019, 02:51 AM
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Default Re: My fix for a ground cable to the engine

buying nuts
but,wait a minute...buying nuts is no that easy. and as there are 2 ways (metric and standard) and how are displayed, is even more fun.
the way to measure the bolt where the nut has to be attached is by measuring the diameter-the round portion where the nut fits.
and in this case is 6mm. but the outside dimension (the hexagon, where the wrench fits to bolt or unbolt the nut) is 10mm (or very close to 3/8").
and for 8mm bolts diameter, the nut is 1/2" (which is not so close to 13mm). and the pitch is another factor.
and the way the labels on the shelves show the size are even more confusing. some show it on metric, others on standard.
so if possible bring the screw where the nut fits, to test the nuts and then buy.
anyway, that is the long story.
 
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  #42 (permalink)  
Old 10-04-2019, 12:50 PM
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Default Re: My fix for a ground cable to the engine

Originally Posted by phil alvirez
buying nuts
but,wait a minute...buying nuts is no that easy. and as there are 2 ways (metric and standard) and how are displayed, is even more fun.
the way to measure the bolt where the nut has to be attached is by measuring the diameter-the round portion where the nut fits.
and in this case is 6mm. but the outside dimension (the hexagon, where the wrench fits to bolt or unbolt the nut) is 10mm (or very close to 3/8").
and for 8mm bolts diameter, the nut is 1/2" (which is not so close to 13mm). and the pitch is another factor.
and the way the labels on the shelves show the size are even more confusing. some show it on metric, others on standard.
so if possible bring the screw where the nut fits, to test the nuts and then buy.
anyway, that is the long story.
The following sizes are based on American National Standard which is very close to the ISO (metric) Standard sizes for nuts. Heavy-duty nuts are larger across the flats. Sizes of some nuts made in China could be anywhere.
Nuts are made to sizes which have manufacturing tolerances so common style M6 (mm) nuts could be from 10.0 mm (.394") to 9.78m (.385") across the flats with a thread pitch of 1.0 mm, and M8 (mm) nuts could be from 13.0 mm (.512") to 12.73 mm (.501") across flats with a thread pitch of 1.25 mm.
We can see that the nominal across flats inch size of the M8 (nut) at .512" is closer to 1/2" than the M6 nut which is .393" is to 3/8".
Flanged nuts are the same sizes. The diameter over the threads on screws varies with the class of screw thread.
 
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Old 10-04-2019, 04:00 PM
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Default Re: My fix for a ground cable to the engine

Originally Posted by phil alvirez
can anybody tell what size is the extra nut that holds in place the new cable? mine does not have any.
and where to get it?
thanks
M6 x 1.00 same nut that is used to attach the coolant expansion tank.
 
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Old 10-06-2019, 03:55 PM
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Default Re: My fix for a ground cable to the engine

thank you sir. regards
 
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Old 11-19-2020, 03:23 PM
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Default Re: My fix for a ground cable to the engine

The reason that I mentioned the security alarm and pneumatic pump was that Rob from Needswings said to check those two potential issues. Thanks for the grounding hint. I was not aware that there was no direct engine grounding. That is just stupid
 
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Old 11-19-2020, 04:38 PM
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Default Re: My fix for a ground cable to the engine

Thanks for the grounding hint. I was not aware that there was no direct engine grounding.
What ?? Of course there is engine to body grounding, raise the car and look on the driver side, you will see the braided cable.

 
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  #47 (permalink)  
Old 11-19-2020, 05:32 PM
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Default Re: My fix for a ground cable to the engine

Originally Posted by old fart
The reason that I mentioned the security alarm and pneumatic pump was that Rob from Needswings said to check those two potential issues. Thanks for the grounding hint. I was not aware that there was no direct engine grounding. That is just stupid
Originally Posted by ala_xfire
What ?? Of course there is engine to body grounding, raise the car and look on the driver side, you will see the braided cable.
OF is addressing me, his remark is in response to a comment I made elsewhere.
And yes, it IS stupid - to provide such a 'round about' return path for the starter and alternator current.
 
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Old 11-19-2020, 06:19 PM
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Default Re: My fix for a ground cable to the engine

Originally Posted by pizzaguy
OF is addressing me, his remark is in response to a comment I made elsewhere.
And yes, it IS stupid - to provide such a 'round about' return path for the starter and alternator current.
Dang ! My palm hurts where you slapped me with the ruler for talking out of turn .......
 
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Old 11-20-2020, 08:01 AM
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Default Re: My fix for a ground cable to the engine

Originally Posted by ala_xfire
What ?? Of course there is engine to body grounding, raise the car and look on the driver side, you will see the braided cable.
When I was reading throught the thread my reaction was to grab Valks provided undercar picture to show the grounding strap, but you beat me to it.
 
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Old 11-20-2020, 10:36 PM
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Default Re: My fix for a ground cable to the engine

Originally Posted by ala_xfire
Dang ! My palm hurts where you slapped me with the ruler for talking out of turn .......
I wasn't George. I didn't even see your post, I was just explaining that he was responding to what I said in another thread...
 
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Old 11-21-2020, 06:37 PM
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Default Re: My fix for a ground cable to the engine

Well, it only took me 3 years to get around to doing James1549's brilliant fix for the grounding cable to the engine. Thirty minutes later, it's done and looks great.
Glad it's done.
 
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Old 01-01-2023, 06:25 PM
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Default Re: My fix for a ground cable to the engine

I think I may have found a new failure mode in our cars. (Unless someone else has ran into this, but I never saw a post about it).

Symptom: At idle, dash backlights seem to "waver" in intensity. It's a gentle oscillation that runs about 2-3 cycles per second, a DMM can't follow this and essentially averages, showing little or no variation.
Because the DMM didnt see it, I really thought it was a variation only happening is certain instrument panel circuits. I should have known better, as it went away above 1500rpm.

So, I really thought that, at worst, it was the alternator not keeping up with load (tho no reason it shouldn't, no one else reports this symptom). I sure have a lot of alternator issues with this car.

While working on my new "battery drain" paper, I got to messing with my battery cables and realized I'd never put the redundant ground in THIS car I had in the Graphite. So, yesterday, I did just that, just on general principles, I put a #4 cable from the bolt James used to the battery negative cable. SUPER easy 'fix'.

Well........................
Today, running around in the car I noticed that the instrument panel pulsing is gone.

I have said it before and I will say it again: This "round robin" ground from block to chassis to battery post is asinine. EVERY other vehicle I have owned had:
A HUGE 2 or 4 gauge battery ground cable to the block.
A smaller, number 10 (or so) wire from battery ground post to chassis.

I've had a LOT of issues with the SE - almost all have been STRANGE electrical issues. This was a cheap, easy fix to one of them - and I wasn't even trying to fix anything, just doing what I think should be done anyway.
 
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Old 01-03-2023, 10:04 AM
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Default Re: My fix for a ground cable to the engine

Tnx Great reading all of this info on grounding! As noted, the Alternator does not provide pure DC. Only when presented to the Battery, (acting as a giant smoothing capacitor) do the pulses become pure DC suitable for running sensitive electronics. Without these important heavy cables, clean connections, and a good battery, you invite trouble.
Update: Feb 3, 2024. replaced my body to transmission ground cable today, noted mild corrosion under the bolt attached to the body. Corrosion never a good thing, so cleaned everything up and ready to go in the spring.
 

Last edited by mrradio; 02-03-2024 at 07:27 PM. Reason: update
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Old 01-03-2023, 10:30 AM
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Default Re: My fix for a ground cable to the engine

Originally Posted by mrradio
Tnx Great reading all of this info on grounding! As noted, the Alternator does not provide pure DC. Only when presented to the Battery, (acting as a giant smoothing capacitor) do the pulses become pure DC suitable for running sensitive electronics. Without these important heavy cables, clean connections, and a good battery, you invite trouble.
That being said is it possible that a weak or damaged battery could allow damage to delicate electronic componenents like the SKREEM?
 
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Old 01-03-2023, 11:07 AM
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Default Re: My fix for a ground cable to the engine

Short answer yes. I have seen many posts on the forum that suggest replacing the battery.
 
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Old 01-22-2023, 01:37 PM
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Default Re: My fix for a ground cable to the engine

MODERATOR NOTE: Post 6 has been edited.
 
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Old 01-12-2024, 07:05 PM
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Default Re: My fix for a ground cable to the engine

Originally Posted by James1549
I just never understood that MB would not have a direct ground cable to the engine block. Grounding to a single fender can't be good for long term.

With that in mind, I found a wide open area at the bell housing. I wanted to use the bolt lower that didn't have a bracket, but it was too close to the exhaust pipe. So here is where I decided:


Pardon the blurry pictures, have an old Fuji FinePix A340 digital that has been dropped one time too many (If anyone has a spare inexpensive pocket digital they aren't using, maybe message me?)...




Cap removed ready to install Scrubbed terminal and post after removing.


My 14 Torx and drive either with or without extension was hitting the transmission tube.


No factory thread lock? I added a dab when assembling.


Scrubbed the metal cable contact point, looked with light & mirror, clean & shiny.


Ran cable along slot between batt and electronics box.


Trimmed the grey cover allowing cable terminal to protrude without losing the cap.


Used a wire tye to secure cable to POS cable


Another wire tye where cable slid along channel, holding it up inside channel.





Looks good, (and) I bet it is much better than the way it was.


.

 
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  #58 (permalink)  
Old 01-13-2024, 01:35 AM
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Default Re: My fix for a ground cable to the engine

Nice job!
I just did this to my car a month ago. Don't forget to do the small ground loop from the transmission to the frame. It's in this thread near the top I think post #18.
 

Last edited by Valk; 01-13-2024 at 11:14 AM.
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Old 01-13-2024, 11:37 AM
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Default Re: My fix for a ground cable to the engine

Originally Posted by M60A3Driver
Nice job!
Don't forget to do the small ground loop from the transmission to the frame. It's in this thread near the top I think post #18.
I've still got to do that upgrade when the weather settles down here!
 
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Old 01-13-2024, 04:02 PM
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Default Re: My fix for a ground cable to the engine

Originally Posted by dedwards0323
I've still got to do that upgrade when the weather settles down here!


FORGOT TO MENTION! The cable I found 1 1/2 weeks ago was the best price I found for it (The price right now is slightly higher, mine was $12.79, I think the more people order it the more they mark it up...). There may be others less expensive but I could not find it. Highest price was 48 bucks... Heck, the cable I bought, you could not buy the bare cable and two lugs for that price PLUS it was free shipping! Here is the link: (
Amazon.com: Standard Motor Products A40-4L Battery Cable : Automotive Amazon.com: Standard Motor Products A40-4L Battery Cable : Automotive
).


.
 
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