Ground Strap Questions (2 Viewers)

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Green Bean

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Is there supposed to be a dedicated ground strap going from the starter to the frame? What about from the transmission to the frame? We are not having any electrical issues with our current setup. We have a ground strap running from the battery to the frame and from the frame to the engine. I've seen some discussions that additional grounds are recommended. The FSM's and Haynes don't seem to address this. Anyone have good OEM specs, drawings, etc.?
Thanks.
 
You can never have too many grounds! I don't remember what is stock, but I added several extra heavy-gauge ground straps between the battery, (200 amp) alternator, starter, engine, frame, and winch. Oh, and some lighter ones from the exhaust to the frame (helps reduce ham and cb radio noise/feedback).
 
I use a ground off the starters bottom bolt, then to the frame.

1641597383635.png
 
Thank you. I have one of Matt's ground wire kits in transit and plan on installing a ground from starter bolt to frame as shown above. I'm a little fuzzy though on where else I should install a ground.
 
The OEM location for the negative ground on early (at least up to 1973) FJ40's was to run the negative cable from the battery to the frame, underneath the battery tray. A grounding cable was also located from the frame (at the bolt for the brake junction block on my '73) to the lower bolt on the starter.

Realize of course that back then, most all of the components (lights, wipers, horn, etc) relied on metal-to-metal contact with the frame or body parts. The body parts were grounded to the frame by direct contact of unpainted metal. This is the reason that over the years, the grounds were lost due to corrosion.

When I restored my truck, I was not going to grind off fresh paint to obtain a "factory" ground. I ran separate grounds to everything, and coated any fasteners that connected grounding wires together with carbon paste to ensure conductivity and impede corrosion.

I believe as time went on and AM/FM CB radios became standard equipment, Toyota had to add more grounds to reduce RF interference. Then, when all the lights became encased in plastic, they ran ground wires to provide proper grounding of everything.

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1641665771001.png
 
Here’s some info I started years ago… as always, please feel free to add more info.


Even though I’ve replaced my frame, engine, transmission, T-case, both axles, 95% of the body, all the brakes, and everything else in between… I’m still learning from others.
 
I thought early rigs’ negative battery cable went to the passenger side front engine mount bolt - on the engine. And there was also a braided ground strap that went from the engine starter mount bolt to the frame near there where there’s a brake line hold down bracket. Early for me is pre- mid’65.
 
I thought early rigs’ negative battery cable went to the passenger side front engine mount bolt - on the engine. And there was also a braided ground strap that went from the engine starter mount bolt to the frame near there where there’s a brake line hold down bracket. Early for me is pre- mid’65.
I'm sure over the years arrangements have changed. You can see in the illustration above that the negative cable was positioned to attach under the battery tray.
 
Not sure where I got my info from. Do you use a tray mount bolt for that connection?
 
Not sure where I got my info from. Do you use a tray mount bolt for that connection?

You will notice in the illustration a nut, bolt and washer combination to connect the cable to the frame rail. There is a hole in the top of the frame rail for the termination.

That being said, I'll hazard a guess that the first time the negative cable needed replacement, your typical mechanic wasn't going to crawl underneath the rig to attach a new cable. Directly across from the negative battery terminal are bolts holding the engine lift hook in place.

Since the "factory" grounding scheme for earlier FJ40's wasn't the best, upgrades as explained by Coolerman et al are the way to go.
 
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You will always get oxidation on the terminals. Adding ground lead where there will be a load helps. For example, a starter would benefit if you add a ground. Otherwise you would be relying on ground that was attached to engine by way of the frame in some cases and they connection may not be a solid connection.
 

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