My fix for a ground cable to the engine
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.
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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×Crossfire1× (08-05-2023)
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.
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.
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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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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×Crossfire1× (08-05-2023)
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Re: My fix for a ground cable to the engine
And yes, it IS stupid - to provide such a 'round about' return path for the starter and alternator current.
Re: My fix for a ground cable to the engine
Dang ! My palm hurts where you slapped me with the ruler for talking out of turn .......
Re: My fix for a ground cable to the engine
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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Re: My fix for a ground cable to the engine
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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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.
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.
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.
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
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.
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Re: My fix for a ground cable to the engine
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:
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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M60A3Driver (01-13-2024)
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Re: My fix for a ground cable to the engine
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: ( ).
.
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K3522 (01-31-2024)
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