Help with grounding please

[kudzu3 323]

I'm getting close to completing my B 80 restoration and have a question about grounding. I wish I knew more about this electrical stuff, but just don't. I know that there has to be ground points but don't know where (or how). Does grounding simply mean that where required, I just need metal to metal? Can someone kinda explain for me please, in a brief simple way that I can understand? Thanks

[chazm 413]

The neg cable goes from the batt to usually a bolt on the eng. & or frame  -  Hope this helps ..Keep us posted 

Edited July 12, 2014 by chazm

[rmaynard 16,226]

In a 12 volt DC circuit, you must have (+) positive, and (-) negative. From the (+) terminal of the battery, a wire goes to the (+) terminal of any item that requires 12 volts to operate. Some of those item are connected to switches, others to relay, still others to solenoids. For example, the starter is the biggest user of 12 volts on the tractor. The (+) wire from the battery goes to the starter through the solenoid, and in order to complete the circuit, the (-) terminal of the starter, which happens to be the case, connects to the engine block, which is connected to the frame, which is connected to the (-) terminal of the battery.

 

So think of everything that is metal, that is connected to anything else that is metal, i.e. engine to frame, frame to dash tower, dash tower to dash plate, dash plate to ignition switch, etc. all becomes part of the ground system by virtue of the fact that the engine and frame and anything else that is connected to them are connected directly to the (-) negative terminal of the battery.

[kudzu3 323]

Thanks! Very good explanation Bob, I believe my simple mind understands. Can the bolts connecting the item suffice as the ground connection, or do I need to remove some paint from the surfaces of the items where they make contact? My thinking (after your explanation) is that the bolts, or connectors will work. Again, thanks for the info, I really appreciate it.

[rmaynard 16,226]

The bolts generally provide a good ground. If in doubt, use a little sandpaper on the hidden side of the fastener to make sure that you have good contact to the metal.

[Martin 2,133]

Very good explanation there, Bob!

 

sometimes a toothed washer or spring washer is all you need to break through the paint. I always use some on the engine mounting point and frame, hood stand etc. doesn't need to be all of them , just one good point of contact and only needed on the parts of the tractor where you need to have an electrical connection. all the part is doing is taking the place of an electrical (-) wire....... you could just do one fastener of every part with a washer or paint removal. take the engine for example, you usually have four bolts and most of the 90s tractors have nylok nuts on the bolts with no spring washer. i put a washer on one of then and that is then the ground path.