Over the weekend fighting to locate a shorted ground in my 73 and cussing the po for what I was finding I began considering a painlesss complete harness replacement. When would you say enough is enough and just replace the entire vehicle harness?
When is it to much? (1 Viewer)
- Thread starter Cruiserman13
- Start date
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If you have the patience and knowledge go for it. Another option would be to remove your existing harness and rebuild it. Coolerman sells the supplies and there are a ton of YouTube videos on how to do the plugs. It’ll add value, drop right in and be correct for your truck.
offrd63
Ain't you done yet!
I think that if you spent as much time fixing your old harness as you would installing a new one, you would save money. Although your the only one that can see just whats wrong with your existing electrical system. I refurbished my harnesses, but I had to remove my harness, lay it out and tack it to a table top and inspect each wire and fix any problems.
brooklyn
SILVER Star
UGH — I took the wiring diagram for my FJ40 to Staples on enlarged it to maximum size - poster size - and the focused on the areas giving me trouble. If you break it down into small subsections it’s much easier to diagnose. Made all sorts of notes on it as well. Been using it for the past 10 plus years.
I also considered pulling it all out, but that seemed like a lot of work when most was working fine. Good luck, it does feel great when you figure it out!
I also considered pulling it all out, but that seemed like a lot of work when most was working fine. Good luck, it does feel great when you figure it out!
I forget who it was, but someone made a color version of the wiring diagram. A search should turn it up. I made a larger format copy for when I redo my harness
Everyone is different. For some, any rats nest is too much, for others pulling the harness (as mentioned above) is not a big deal.
More detail is needed to help answer your question. Also, there are a couple of excellent shops in the Treasure Valley where you could get some help as well as a bunch of very knowledgeable crusierheads.
forum.ih8mud.com
More detail is needed to help answer your question. Also, there are a couple of excellent shops in the Treasure Valley where you could get some help as well as a bunch of very knowledgeable crusierheads.
ID- Treasure Valley Land Cruisers
forum.ih8mud.com
Mopdog
SILVER Star
I had the opportunity to see a really high end custom 43 a local shop built for a local executive here in Boise. He sold me on the American Autowire harnesses. I’ll be starting on my complete rewire soon. With the SBC, Chevy column for the sag power steering, and deplorable condition of my stock harness it is a no brainer for my situation.
- Thread starter
- #8
I finally finished my 3fe conversion after fighting a rats nest cruiserparts called a conversion harness and some bad relays and efi switches. Now my original harness is shorted and as I troubleshoot I think every place I dug into the po had been there and cobbed some wires together that makes the fuses and diagrams less or non helpful. Frustrating. Check out this conversion harness.Everyone is different. For some, any rats nest is too much, for others pulling the harness (as mentioned above) is not a big deal.
More detail is needed to help answer your question. Also, there are a couple of excellent shops in the Treasure Valley where you could get some help as well as a bunch of very knowledgeable crusierheads.
ID- Treasure Valley Land Cruisers
I've been 'restoring' the wiring on my '63 for about a year now. Luckily the PO's mostly added their wiring and left the original in place.
The wiring diagrams in the FSM and Haynes book are pretty accurate and is a good reason to keep it original. If you can see a wire's colors
you will always know which one it is - very helpful IMO.
I would also like to see/have a color wiring diagram and a source for OEM color wires.
The wiring diagrams in the FSM and Haynes book are pretty accurate and is a good reason to keep it original. If you can see a wire's colors
you will always know which one it is - very helpful IMO.
I would also like to see/have a color wiring diagram and a source for OEM color wires.
Ugh. That's crap.
I would determine how much of the original wiring was still good, and decide from there. Since you have a different engine harness (at least),, it may make sense to put in a complete aftermarket harness. Keep in mind though, they are not plug-n-play, but it may be less work than repairing the original.
pb4ugo
SILVER Star
Google search coolerman FJ40 and you will find his website. He probably has a wiring schematic for your 40. He also sells the majority of plugs, terminals and proper color wires. Removing the wiring harness from your 40 is fairly easy.
Thanks for the coolerman site idea. My wiring harness is fine where it is for now until the 'big' resto, that is.
I do want to replace a few wires that are worn or cut.
C6H12O6
SILVER Star
I've been pretty lucky so far with wiring in my '74, but what I have noticed is that most of my issues are from dirty, dried out, oxidized connections at the old, stock connectors. When I take them apart and clean up the connectors, add some dielectric grease, most things seem to work fine. The tricky ones that don't are the ones that look outwardly to be ok, but still don't conduct. Just replacing the connectors can help, but when you are dealing with 40+ year old wires with brittle insulation and green crust on the copper, it gets to be a real pain to deal with. I have defaulted to the idea that a less invasive approach with old wiring is better, but when/if I get to the point where I'm tearing into the loom and tracing down actual wiring issues, as opposed to just bad connections, I'd be looking at updating to new wires, better connectors, and beefing up the wire gauge in some critical areas where the OEM size just barely cuts it—charging circuit, headlights, etc.
offrd63
Ain't you done yet!
When I repaired my 63 harness , I would sometimes have to replace most of a some of the wires . I made sure though that I could splice in the original color code so that at least the beginning and the end of each wire had the original colors showing. Like you said "if you can see a wire's colors, you will always know which one it is"
I wanted to be sure that the next owner of my rig won't be talking about his piece of s*** PO
Sorry to get all technical and specific about semantics... But "shorted ground"?
Having a brief background in electrical work (2 years as an apprentice electrician, before going back to college...), a short is where electricity is allowed to reach ground before it should. In an automotive electrical, generally, this is when your 12v positive connection is in direct contact with the negative (chassis / ground), hopefully blowing fuses, or else sparks, heat, fires....
And if you have multiple spots on the harness where you feel this is a risk or have been having issues with it, that's when this is "too much". If you're not sure every circuit is fused, that there is an appropriate fusible link on the battery (cause there is 6 feet of wire going through the firewall between the battery and the fuse block) and your main positive connections aren't properly insulated, it's at risk of electrical fire and needs to be.
If you are finding charred wires, melted insulation, there's a problem. I've found spots that were just poorly crimped connectors (on the white wire off the alternator...) that are quick and easy to correct so that they will properly work without tearing the whole thing apart or replacing. But it was easy to identify on mine where the PO modified it (different tape and that s***ty parts store plastic cover used). And if you see anything with really light, 16 or 18 AWG sized wires, be suspicious of them, they could be fine, wiring needs to be sized considering not only amperage but also length, smaller gauge wiring might be fine for very short lengths.
Or if lights and other accessories continually fail, though this is commonly grounding issues, where the chassis is used as a 12v negative bus and there is high resistance back to the battery due to corrosion or paint.
Being tangled, wrong colors, lots of splices, is not pretty, but can be fully functional and safe. It's really just how much a nice clean appearance matters to you. Even brand new cars are often full of unused wiring and connector under the hood where similar wiring harness are used regardless of options of different equipment in different markets. It's not a functional problem.
Having a brief background in electrical work (2 years as an apprentice electrician, before going back to college...), a short is where electricity is allowed to reach ground before it should. In an automotive electrical, generally, this is when your 12v positive connection is in direct contact with the negative (chassis / ground), hopefully blowing fuses, or else sparks, heat, fires....
And if you have multiple spots on the harness where you feel this is a risk or have been having issues with it, that's when this is "too much". If you're not sure every circuit is fused, that there is an appropriate fusible link on the battery (cause there is 6 feet of wire going through the firewall between the battery and the fuse block) and your main positive connections aren't properly insulated, it's at risk of electrical fire and needs to be.
If you are finding charred wires, melted insulation, there's a problem. I've found spots that were just poorly crimped connectors (on the white wire off the alternator...) that are quick and easy to correct so that they will properly work without tearing the whole thing apart or replacing. But it was easy to identify on mine where the PO modified it (different tape and that s***ty parts store plastic cover used). And if you see anything with really light, 16 or 18 AWG sized wires, be suspicious of them, they could be fine, wiring needs to be sized considering not only amperage but also length, smaller gauge wiring might be fine for very short lengths.
Or if lights and other accessories continually fail, though this is commonly grounding issues, where the chassis is used as a 12v negative bus and there is high resistance back to the battery due to corrosion or paint.
Being tangled, wrong colors, lots of splices, is not pretty, but can be fully functional and safe. It's really just how much a nice clean appearance matters to you. Even brand new cars are often full of unused wiring and connector under the hood where similar wiring harness are used regardless of options of different equipment in different markets. It's not a functional problem.
- Thread starter
- #16
When 12 volts meets ground in my situation does not mean blown fuses or heat etc. With the negative battery cables disconnected from the battery I can put my negative lead of my meter on the bare negative post and the positive lead of my meter to the body/frame of my rig and get a reading of 12 volts the same as touching the positive post of the battery. The amp pull is about .09. I have isolated to the wire ppl/red wire leaving the fuse block(does not blow any fuses). Now the fun, that wire feeds a few different things but I have found several more items spliced into that circuit. So obviously there were problems in the past and the po used that circuit as a good one to use witch also means when if I put them back I am creating more problems. Some ones short cuts are now causing me grief. This all after hours and hours of tracing and cutting and testing and cutting then taping and looming a conversion harness into it. For two days it was perfect and now this. My fear is after I get this fixed then what! A new harness may give some comfort in removing the unknown and reliability questions. That said I love the idea of keeping original parts in place.
Well, you've got me wanting to go test this...
But, if there's any switch closed (turned on), and passing through something, ya, it's charging the whole chassis as it tries to get back to the battery negative post, which should be measurable with your meter. Though, I'd expect more resistance to drop the voltage, especially if it's not blowing a fuse. Because, ya, a light bulb is basically just a piece of wire in glass that voltage goes through a little (or a lot) slower than the rest of the wire, and pretty much everything else conducts power to some degree of another just like that...
If it's that one circuit, follow that wire. Or just cut it off or pull out of the fuse block and see what isn't working anymore.
Really, if you think you're not going to be happy with it until you do, than just do it. I'm thinking about pulling my whole harness out just because it's too dirty. Any time I touch it my hands get dirty, inspecting the wiring harness gets me dirtier than changing the oil. (And I have a couple issues, mostly minor really, starter was failing, and running a new wire from the ignition switch seems to have mostly fixed it, need a few new accessories, power seats, winch, etc., would like brighter headlights.) And the PO painted a lot of the harness, just kinda bugs me. At some point, if you believe it's something you want to do, just do it, don't expect others to see the logic (fixing land cruisers, not storming any capitals.).
It's not that hard. @Coolerman shared a long write up a while ago on how he organizes and cleans them up and wraps / unwraps them. Key point is labeling everything before / during removal, then lay out on a table or board tracing general same shape / path as it would be installed. And he apparently sells a lot of the correctly colored wires and connectors, I've generally been too quick to ignore correct coloring and just use spade terminal on everything I don't have correct connectors for (sometimes they come loose...). I've pulled the whole harness out of a '71 without cutting anything, it wasn't that challenging, the little metal tabs that bend over the harness from the factory are easy to release. And have read a couple other people share their expirience, having never done something like this before, one was spurred to by the white wire shorting on the back of his ampmeter (with no fusible link melted the whole wire and smoked up his garage overnight).
I personally don't see the value of "painless" harness. Does is come with connectors that match right up with all the stock Toyota switches and accessories? If not, it's just a bunch of wires with instructions that are probably going to take me longer to understand than just following the stock harness with all new wire. But that's going to be a personal thing. Having it pulled out, inspected, and knowing where every connector goes would give me as much faith in the old harness as having a new one, maybe more.
But, if there's any switch closed (turned on), and passing through something, ya, it's charging the whole chassis as it tries to get back to the battery negative post, which should be measurable with your meter. Though, I'd expect more resistance to drop the voltage, especially if it's not blowing a fuse. Because, ya, a light bulb is basically just a piece of wire in glass that voltage goes through a little (or a lot) slower than the rest of the wire, and pretty much everything else conducts power to some degree of another just like that...
If it's that one circuit, follow that wire. Or just cut it off or pull out of the fuse block and see what isn't working anymore.
Really, if you think you're not going to be happy with it until you do, than just do it. I'm thinking about pulling my whole harness out just because it's too dirty. Any time I touch it my hands get dirty, inspecting the wiring harness gets me dirtier than changing the oil. (And I have a couple issues, mostly minor really, starter was failing, and running a new wire from the ignition switch seems to have mostly fixed it, need a few new accessories, power seats, winch, etc., would like brighter headlights.) And the PO painted a lot of the harness, just kinda bugs me. At some point, if you believe it's something you want to do, just do it, don't expect others to see the logic (fixing land cruisers, not storming any capitals.).
It's not that hard. @Coolerman shared a long write up a while ago on how he organizes and cleans them up and wraps / unwraps them. Key point is labeling everything before / during removal, then lay out on a table or board tracing general same shape / path as it would be installed. And he apparently sells a lot of the correctly colored wires and connectors, I've generally been too quick to ignore correct coloring and just use spade terminal on everything I don't have correct connectors for (sometimes they come loose...). I've pulled the whole harness out of a '71 without cutting anything, it wasn't that challenging, the little metal tabs that bend over the harness from the factory are easy to release. And have read a couple other people share their expirience, having never done something like this before, one was spurred to by the white wire shorting on the back of his ampmeter (with no fusible link melted the whole wire and smoked up his garage overnight).
I personally don't see the value of "painless" harness. Does is come with connectors that match right up with all the stock Toyota switches and accessories? If not, it's just a bunch of wires with instructions that are probably going to take me longer to understand than just following the stock harness with all new wire. But that's going to be a personal thing. Having it pulled out, inspected, and knowing where every connector goes would give me as much faith in the old harness as having a new one, maybe more.
Do it right the first time with correct colors - and never have to deal with it again and if you do you can trace the problem easily.
mid your just trying to get it running right so you can drive it once in a while planning for an eventual bid resto. I’d leave it in and tackle necessary wires based on your diagnosed issues desired to fix. A couple switches on your dash panel not working isnt the end of the world and account for plenty of wiring.
get the correct schematic from Coolerman website:
and then tackle one thing at a time - don’t get distracted by other wires you run into that you can fix later. It makes your head blow up. But if you just fix one thing at a time (trace wires, fix issues, test, repeat) - next thing on list. Made it way easier on me and my head was blowing up for the first week just realizing how much unraveling I really had to do to figure out what my PO did. I ended up Untaping the entire thing.
Good luck - there are really good threads here so don’t forget to use that search button about whatever issue your dealing with.
mid your just trying to get it running right so you can drive it once in a while planning for an eventual bid resto. I’d leave it in and tackle necessary wires based on your diagnosed issues desired to fix. A couple switches on your dash panel not working isnt the end of the world and account for plenty of wiring.
get the correct schematic from Coolerman website:
and then tackle one thing at a time - don’t get distracted by other wires you run into that you can fix later. It makes your head blow up. But if you just fix one thing at a time (trace wires, fix issues, test, repeat) - next thing on list. Made it way easier on me and my head was blowing up for the first week just realizing how much unraveling I really had to do to figure out what my PO did. I ended up Untaping the entire thing.
Good luck - there are really good threads here so don’t forget to use that search button about whatever issue your dealing with.
