[Guide] Seatbase stud bolt Earth / GND connection

EAN

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T6 Guru
Thought I’d post how I did each of my GND connections through a seat base mounting stud bolt.
I couldn’t use the factory GND studs under the seats because on the drivers side it had been removed to allow fitment of the diesel heater ductwork and on the passenger seat it was going to foul my Roamer 230SB battery install.

Unfortunately, I had already started before deciding on doing a detailed breakdown, so missing pictures from stages 1-3.

The seat studs have a protective coating which isn‘t very conductive, so they are not an ideal GNDing point unless you do something about it.
Forming a good conductive path is everything, so;

1) With the seat bases out, I removed one of the rear seat studs from both the passenger and drivers side; I chose the near side of each.
2) I removed the protective coating from the bottom thread of each stud and the top and bottom flat mounting faces.
3) I carefully ensured there was no paint on the van floor where the stud mounting faces bolted down.
4) I then applied MG Chemicals 847 carbon conductive assembly paste sparingly to the bottom threads and slightly more liberally around the bottom flat mounting faces and the bare van floor, then reinserted the seat base mounting studs and tightened them fully. I used this assembly paste to protect the bare metal and to ensure a highly conductive interface.
5) Then I removed the paint from the bottom of the seat bases where they would contact the seat base mounting face and the top of the seat bases where my GND connections were to be made.
6) Applied more 847 paste to the bottom bare metal GNDing point on the seat bases.
7) Then refitted each seat base, using 3 of the original seat base nuts, leaving each GND seat base stud unconnected.
8) Applied more 847 paste to the top bare metal GNDing point on the seat bases.
9) Attached my 35mm2 negative cables using 10mm copper tube terminals and secured each using a flat washer and locknut.
10) Finally I measured the resistance between each of the negative cables and the factory GND stud to ensure I had a really good GND.


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How poor are the untreated bolts as a ground connection? I expect many of us have just exposed the bare metal on the base.
 
Whatever the treatment on the upper stud the limiting factor is probably the condition of the tread in the body.
I suspect this is partially painted during manufacturing.
 
Reviving this in the hope someone can help.

Other forum members have directed me here. Like OG poster I can’t access the factory grounding point so am using seat bolt.

But am getting some odd numbers that folk suggest may be related to the use of this bolt.

Can I ask, how I remove the actual bolt to clean etc. do I need to access under van?

Thanks in advance from a frustrated Xmas Luddite
 
The seat base studs just unbolt from the top; no access beneath required.
You do, however, need to remove the seat base: So remove seat, remove seat base, then remove any seat base stud as required.
 
And the clean up you described helpfully in steps, did you need to sand/ soak etc? Before applying the paste?

I am a bit lost to be honest
 
And the clean up you described helpfully in steps, did you need to sand/ soak etc? Before applying the paste?

I am a bit lost to be honest
Yes I used some fine emery cloth: In my case I used a spare washer I had and stuck the emery cloth to it with some double sided tape, and then spun it on the seat stud so I only removed as much paint as I needed to.
 
I’m getting readings of 0.08 from shunt chassis side to the seat base de facto grounding bolt using multi meter on 20 DC settings, but I don’t really know what that means
 
I’m getting readings of 0.08 from shunt chassis side to the seat base de facto grounding bolt using multi meter on 20 DC settings, but I don’t really know what that means
My resistance is pretty much unmeasurable with a multimeter.
To check your ground measure from a different vehicle ground stud somewhere else to your seat base stud earth connection: Set your multimeter to ohms, lowest resistance setting you have, connect the two multimeter leads together and make a note of the reading (that’s the resistance of the test leads). Now put a multimeter lead between a known vehicle ground and the seat base stud being used as an earth. Subtract the resistance of the test leads and then what you have left is the resistance to chassis ground.
 
 
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