67 Cj5 Build Thread By A Rookie

Looks like a good idea, if you can get a good cover for those hot terminals. You don't want exposed hot wires(post) on the fender for a wrench to be accidently dropped on them and short out.

 

Do you need an extra terminal strip? Are your relays socketed? I would minimize the exposed terminals and run my feed wire directly to the socket leads.



Here I have used uninsulated crimp connectors to join the large long wire to the feed wires of the relays. Soldered and covered that with adhesive heat shrink. The wires have been pulled out of the loom.

Here's the power distribution on my J20:


My preference is to not have any exposed electrical stuff, other than the battery cables and the solenoid. Especially as little unprotected wiring as possible.here there is one short 10 ga wire from the solenoid that feeds the lights CB. Then I have a small 14 ga jumper to the ignition module CB. The black fuse holder was supplied with the EFI kit and its short end goes to the terminal of the ignition CB.

Not presenting this as the way to do wiring, but instead to point ouf some of the issues as I see them. IMO having exposed hot terminals asks for trouble. The whole car is one big ground plane, and any accidental contact between a hot terminal and any part of the car body will be bad. You need to protect the car from the battery - it's like a bomb, with similar power.

You also need to protect the wiring from pinching and abrasion. I put plastic wire loom on everything (cheap insurance) or you can sheath a single wire in vacuum tubing. For the race cars, Brian would glue the wires down with that yellow weatherstrip adhesive along their entire length. No movement, no abrasion. Any sheet metal pass-throughs need to be protected with a grommet or similar. Something you should be especially aware of with a Jeep.

Sorry if this is seems preachy and too much safety-ism.

 

Not preachy at all. I really appreciate the detailed feedback. I have college physics level knowledge of electricity - in other words, no practical knowledge! Part of what I have been doing is leaving myself bail outs as I do, so I have used bullet or spade connectors (crimped, heat shrink insullated) in some places where you used butt connectors, just in case I needed to make changes or if something like the relay goes out. This looks like a place where a pernament connection would be better.

What about the ground? I used an online wire gauge calculator and it indicated that 6ga was good enough, but again that is book knowledge, not practical knowledge.

edit: This bus bar is only for the grounds I mentioned already, not tail lights, instruments, or engine.

 

I return the ground through the body steel. I deemed that good enough. Certainly the body steel has the amp capacity and sufficient cooling to return whatever I send to the lights. My negative battery cable has a pigtail meant to go to the body steel.

Possible you could reduce voltage drop by using a dedicated ground wire. Will the improvement be detectable? I don't know. There is a chapter about wire loss in the article I posted. http://www.earlycj5.com/xf_cj5/index.php?threads/142321/#post-1571295 Later in the thread I suggest that the sheer size of the body steel as a return conductor possibly makes up for the higher resistance of steel. Arguable. Measuring very small resistances is difficult - you might be able to do it with a meter like this https://www.midwestdevices.com/index.php Likely not with your Fluke multimeter. I would expect your meter impedance and lead resistance to swamp out any tiny differences of fractions of an ohm.

What are the devices? Just lights? IMO 6 ga is excessively large for anything other than the starter motor. JMO.

Don't want to be overly negative-sounding. You are right, the exposed ground bus bar does not have any safety issues. However, I'm not sure it does more for you than provide an aesthetically pleasing place to terminate your wires. It will work fine, and look good.

 

Tim, I really like your direct, detailed, data driven style and don't find it preachy or negative. I'm trying to avoid crashing or burning my car, and I don't always get subtle hints!

I had 6ga left over from my alternator ground. it goes directly from the bus bar to the clean metal on the frame. The devices going to the bus bar are:

2 x relay (switch) grounds (14ga?)
1 x horn ground (14ga)
2 x headlight grounds (16ga)
2 x park/turn light grouns (18ga)

It was a simple, clean, relatively inexpensive way to attach multiple grounds.

 

Wiring - done! (Hopefully)

 

Great job on the wiring, it looks clean!

 

x2, nice job

 

I just encountered my first big problem. A while back, I determined that my engine/transmission/TC was rotated slightly on its mounting points when I saw how my tail pipes weren’t at the same position compared to the rear tires (exhaust dumps out in front of each rear tire). I didn’t change any of the parts, so my conclusion is that I mounted it malrotated.

My mechanic saw it and didn’t think it made sense to remount everything because it was a small amount compensated by the u joints in the drive shafts. My plan was to modify the tail pipe initially and then ultimately route the exhaust out the back so I choke on less fumes.

Cut to November. I reinstalled my fenders and the drivers side header contacts the fender. It cooked off some of the paint on the inner wheel well and deformed the steel from the heat. Now I need to figure out how to rotate the engine/Tranny/TC into the correct position with the jeep essentially fully assembled!

My thoughts are to either take it to a shop or bring back my friend’s engine lift, lift the engine slightly, loosen all attachments, and see if I can nudge it back in place.

Will that work? Seems simple enough that I must be missing something very obvious.

 

Had you considered the shorty headers that dump inside the frame rail (I presume)?
https://www.novak-adapt.com/catalog/headers/buick-90-degree-v6-headers/

You could join them to a nice quiet single exhaust that dumps at the rear corner.
Or go with sturdy cast iron manifolds.

Maybe take the fender off and recess it to clear the header pipe? Plenty of room for that, I'd think.

This is just me - not a fan of tubing headers. Hot, noisy, fragile, leaky race car tech. Otherwise they are great!

Afterthought - I would point out that the frame and front clip of a Jeep twists and moves a lot when in action on the trail. A lot. Guessing you need a couple inches clearance there.

 

Just support the motor from above or below and do what you need to do. I've used a 2x4 from cowl to snow plow to lift my motor. I've used a blocks from below, straps across the frame rails, Saw horses, Straps to the roll bar, etc etc...

Support aside now you need to figure out what's going on. You know the motor mounts are left and right specific right?

 

They are new motor mounts that weren’t exact matches, so I spent a lot of time looking into this. I will recheck.

 

. You know the motor mounts are left and right specific right?[/QUOTE]

THIS!

 

Comparing the two old mounts is difficult because the rubber on the passenger side is deformed. The old mounts differ in the following ways:
Passenger is stamped “R” (new ones aren’t marked)
Driver has a notch at the trapezoidal part that sits outside the tab.

The tabs that bolt to the frame are farther away from the engine mount holes, but that part of the rubber is peeled away from the wall of the bracket, so I can’t tell whether that is a fake difference. Any other distinguishing features?

 

For future reference, here is a pic that Sam from Partsdude sent me showing the right and left motor mounts. I’m not sure if I’m going to be able to tell them apart on the vehicle, but the most distinct feature to me is the angle of the tabs where they mount to the frame. Drivers side slopes toward the engine and passenger side slopes away from the engine.