Thread: Best ways/locat to ground

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I want to make sure my 32 is grounded well.

Please tell me what should be used to ground it- What type of strap and where to buy it. Also, should I have one that grounds the engine to the frame and then one that grounds the Fiberglass body to the frame?

Thanks.

Originally Posted by bucs012

I want to make sure my 32 is grounded well.

Please tell me what should be used to ground it- What type of strap and where to buy it. Also, should I have one that grounds the engine to the frame and then one that grounds the Fiberglass body to the frame?

Thanks.

Since fiberglas is not a conducter there isn't any point unless your talking about a metal frame inside the body, then yes! add a ground strap/wire. Same as the engine block, add a ground strap/wire to make a good circuit. Find a topic (post) called Electricals Phew, it's got a lot of good discussions about wiring and manufacturers and such. Hope it helps!

Autozone has a universal ground strap for cheap that will work fine from motor to frame.....
http://www.autozone.com/R,89628/stor...ductDetail.htm
For underdash, I didn't have a central metal mount for the gauges, switches, etc., so I went down to the local metal salvage yard and picked up a solid brass bar, 1/2" X 1" X 6". I drilled and tapped it for screws, mounted it under the dash and connected a 10 ga wire from it to the frame. Then it was a simple matter to tag up ground lugs from instruments and switches to the brass bar and much less wiring mess. Doing the same thing at the back of the car can clean up the whole thing. 10 ga wire with crimp on lugs will work fine for brass bar to frame. Lesser wire gauge, such as 12 ga will work fine from tail light/brake light to bar. Coat the lug connections with RTV to keep moisture out. Where you attach lugs to the frame, sand off a bright spot, attach the lug, then coat the whole connection with RTV.

Another option that I like for the RTV is dielectric grease,I use it at every connection electrical related.I use it very liberally ,smear it on thick!!!!!!!!
The brass bar is a great Idea and will work very well.

Just some random comments here. Tech1, that brass bar idea is very good and maybe I can still clean up my mess under the dash. I do have a 1" square tubing framework inside my fiberglass body and I have a short length of "00" gauge welding cable with brass terminals pressed onto the ends connecting an engine-to-transmission bolt to the framework. On the other side of the frame I have a long length of "00" gauge welding cable from the (-) battery forward to another engine bolt on the transmission mount. I am commenting on this because I have another "00" gauge welder cable from the (+) battery terminal on the right frame rail to the starter and my TPI guru told me something I really do not believe? He said a smaller gauge wire to the starter would be better since my large gauge wire would soak up too many electrons, too much amperage bleeding into the large wire? I know about what is called "fanout" limit of current from power supplies in electronic circuits for mineature electronics but I wonder if I have a cable which is too large for the starter from the battery? I was trying to just make a really good connection but I can see on the "water flow" model of elctrical current that a large cable could soak up a lot of electrons. Is my cable to the starter too large (gauge too low)? The cable is pretty long and I am just trying to make sure I get good amperage to the starter. Anyway on the ground connection I have been using the upper bolts on my door hinges on the inside which have long threaded sections to attach my ground wires from several instruments and that keeps the wires up high out of sight but not as neat as what Tech1 suggested, I will rethink that.

Don Shillady
Retired Scientist/teen rodder

Don, I have never heard of "soaking up too much electrons". Larger gauge wire offers less resistance to current flow and thus is not prone to over heating. A good strong battery will not see that much impedance in your circuit and you should not have starting problems on hot summer days.

Don, I remember a shop teacher who told us to hold both ends up of any wire we were handling to prevent the electrons from falling out. I suspect he may have been related to the clown who told you that.

Tech1 and NFTDAY, Yes, after I heard that idea from the TPI Tech guy I scratched my head. When you think about it the copper in the "00" cable already has electrons at rest so the only flow is the demand of the starter and thus the resistance/impedance should be low with a thick cable. However I do recall in my experience with solid state electronic devices that if you use a power supply which is too small the "fan out" distribution to all the paths in the circuit will be starved for electrons, but with several hundred amps available from the battery, at least for a few seconds, there should be no problem. You note that I have not changed my set up, I am only asking for clarification! However I am at the mercy of the TPI Tech guy who knows his specialty of the TPI wiring harness backwards and forwards, but maybe has never solved a problem with Kirchoff's law of summing the amperage at every node in a circuit! I am close to finished with only a connection of the brake light circuit on the hydraulic pressure switch and the power connection to the radio yet to do. I have recently spent a fair amount of time and thought on connecting the four speakers from the radio in proper phase and bit the economic bullet to purchase a better "marine" grade radio since I am stuck with my mistake of carving out a large hole in the dash for a radio just below a probable leaky windshield gasket. Most of the circuits I have installed are already the third version as I gradually improve the "mess" with the intention of adding a LOT of ties to clean up the circuits when I finally get ready for the first startup of the engine. I plan to install the 1.5 ratio rockers initially and then go back to the 1.6 ratio rockers after some break-in time. I may still revert to Tech1's idea of the brass bar ground. Thanks for the feedback!

Don Shillady
Retired Scientist/teen rodder

I have two of these--one under the dash and one behind the seat for ground wires. They worked pretty slick for me.

www.madelectrical.com/catalog/cn-1.shtml

Regarding a bus bar...copper is better than brass. If you go to the Depot or Lowes, you can buy a copper bus bar that is intended for elelctrical enclosures....it already has the holes and set screws for your wires. You can get them for various sizes of wire too.

Ground continuity is obviously a necessity. Crimp on terminals are prone to vibration loosening causing intermittent connections.

Originally Posted by robot

Crimp on terminals are prone to vibration loosening causing intermittent connections.

That would depend upon what is being used as a crimping tool. There are many DC-8's, 9's,10's amongst others flying that have a multitude of crimp connections.

Absolutely true...most folks do not invest in a decent set of crimpers.... we probably have $10,000 in crimp tools here and still dont cover all terminal styles. You sure dont get away with crimping an aircraft connector pin with a pair of AMP pliers!!!. Also, an aircraft wire or cable is properly supported and the back shells have their own strain relief. Most car builds have zero support near the crimped terminal and people typically bend the wire at the terminal....

Originally Posted by robot

Absolutely true...most folks do not invest in a decent set of crimpers.... we probably have $10,000 in crimp tools here and still dont cover all terminal styles. You sure dont get away with crimping an aircraft connector pin with a pair of AMP pliers!!!. Also, an aircraft wire or cable is properly supported and the back shells have their own strain relief. Most car builds have zero support near the crimped terminal and people typically bend the wire at the terminal....

Agreed, that's why I solder most connections especially if they are going to carry any type of load.