FJ40 grounds (Where are they?) (1 Viewer)

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Trollhole

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Another post in the 55 section has me thinking. How many ground are there on the early and late 40's and where are they? Might be a good way of preventing an issue before it happens.
 
ground strap

The only actual ground strap I am aware of is the one from the starter mount to the frame.

39 in the pic
ground.gif
 
The wiring harness has a ground connection on the right, inside part of the frame, midway between the front and rear spring hangers.....
 
My 12/74 has the ground midway down the right side of the frame, like Poser states, but also has one attached to the inside aft bumper.

Joe
 
I know of three on my 2/71: Engine block to frame, mid frame ground near the transfer indicator wires and the license plate light (tailgate to body) ground.

The EPC refers to these grounds as cable bonds. :D

However, since there are so many things that ground to the body, you should add a good ground from the cowl to the frame, and from each fender to the block or frame. I also plan to ground my alternator case directly to the block. I powder coated the bracket and don't want to rely on it to provide ground.
 
There is also a ground wire from the alternator to the voltage regulator and a ground wire for the fuel sender. Most power consuming devices are grounded through their case where it mounts to sheet metal.
 
On later wiring diagrams Toyota separates the grounds into 3 groups as shown in this copy of the bottom LH corner of the first page of the 1983 version:

Grounds1983.jpg

:beer:
Grounds1983.jpg
 
Hi Tom! My Red 1983 basket case is showing more and more wiring problems, they installed an alarm and it looks like every time they had a problem they just rewired...instead of solving the problem. I need badly a wiring diagram to chase some issues I have. Battery & Oil pressure gauges work on my dash now that I fixed them but the wiring was moved to external gauges.... its a mess, same with rear lights, brake lights don't work etc etc.

Also, sadly I have a tiny crack in my block, seeping water. Don't really know how I will resolve that. I wanted a project car and I got one :)
Thanks Tom Henry
 
I have just striped down my 1976 HJ 45 tub harness down to repair Po bodges and add some wires for spotlights and day runner lights and all the earth wires seem to only connect to the tub through the voltage regulator body. I couldn't find any decent connection between the tub and the frame.

I have added to this and now I have a 12 gauge lead running from the ground point in the frame by the starter up through to the bulkhead by the indicator relay. All my headlight grounds spur off this and I have run extra for my front indicators as I have fibreglass guards.
 
I rewired my 1970 FJ40 in late 2013, early 2014, can't remember. I used an American AutoWire Hwy 15 kit. I also ordered some plastic plugs and the various male and female spade terminals, bullets, etc. I ordered and use military style battery post clamps. These come in positive and negative terminal sizes, since they are different and you don't have to undo the clamp to undo the wires, a major plus as we know what happens to battery post clamps after a couple of uses. I also ordered new ground cables. Not just one like the fellow had from the post to the lifting tab on the right front corner of the block. I ground from the battery to the frame just below the battery. From the block to the frame, from the block to the body, from the body to the frame. I think I have five total grounds. I split my harness at the firewall and run left and right. The headlights are on relays, four total, and the left runs off the alternator and the right off the battery.
 
Early 40's have very few grounds. Later more from what I have seen. On my 4/1973, there was only two grounds that I can remember that are not part of the individual components. The ground wire near the transfer case, or midway between the spring hangers as others mentioned above and showed a picture of is for the fuel level sender, nothing else. It is simply a jumper wire from the ring terminal at the level sensor cover to the frame because the fuel tank is mounted on cloth strips from the factory. The only other ground wires were the black and yellow heavy cables from the starter stud/bolt to the frame, and the negative battery cable to frame, in front of the battery tray.

Now each light fixture has a white and black wire on it, but each of those either runs an inch or two and attaches with the light attachments, or disappear back into the loom. The headlights and wiper motor ground back through the loom to the windshield wiper switch mounting nut. The voltage regulator on the firewall is also a critical ground for the charging circuit. Idle solenoid grounds through nut and stud connections of the carb and manifolds. Distributor grounds to the block. Gauge cluster must ground through headlight ground circuit to the wiper switch.

Things I have changed: Ran a longer ground wire from starter to join the battery ground wire with one bolt. That is your heaviest circuit, poor ground on either of those can cause hard starting or in my case burned up two starters due to the contacts welding together from the increased resistance of poor grounds at the bolts to the frame. I soldered a ground wire to the license plate light housing and ran it into the rear and under the mounting nut for the singular backup light on the pre 74's, which also grounds right there, because the hinges on the barn doors get loose and rusty and make a poor ground for the light. I could see the light going off and on while driving over bumps, would also flicker and such when opening the rear door. Ideally the headlighs at least need a better ground, found that out after taking the wiper switch out, messed up the ground, couldn't figure out why the headlights wouldn't work. I have fought corrosion at the marker/turn lights and poor grounding also.

Later models seem to run the white and black wires back in the loom. If they follow the same setup as the 60 series and pickups and such they all come together in one to a few ring terminals near the fuse block. I would suspect late 40's probably had a body to frame ground, I don't think any pre 80's had one, just relied on the body mount bolts. I'm nearly sure I have seen body to ground wires on my 60 series under the floor boards, there is also a firewall to engine block ground wire on most newer trucks I've worked on. That is why I suspect the last 40's had a body ground someplace, since it was integrated on the 60 platform. Oddly the license light on a 60 series still relies on the hinges for a ground. The rear dome light also relies on the rear hatch for a ground, and when it can't find one, it will go through the defroster wire circuit and light up the orange indicator light on the defroster switch, eerie.
 
All my grounds are separate wires run back to a main ground on the frame-The engine-to frame has three brazed connections--2 on the left side, one on the right.(did it that way because there were more engine bolt holes on the left)
If I have an electrical prob which might be ground related, I only have one place to look (initially). Did take a lot of extra wht w/black stripe wire, but now at least I don't have to fiddle with the loom--

ground connections1.jpg
 

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