Electrical gremlins galore (1 Viewer)

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Joined
Sep 9, 2020
Threads
27
Messages
152
Location
Oregon
PO told me upon buying to expect the unexpected and there was a bunch of inconsistencies with the FJ40’s electrical system so I expected a challenge. It has a GM column adapted to the 77’s wiring, and he said he has never had working turn signals. I spent today chasing leads and got the signals operational, the problem I was finding was with everything else. No consistent power supply to the brake lights, heater or wiper motor. At one point I had a hot at the brake light feed wire and then just like that it was dead. Same with the heater, I had it on with the truck running and at one point the fans came on and then they were gone. Really wierd. Ill go back at it tomorrow. Here are a few misc pictures of some of the wires I found tucked up under the dash after removing the 80’s Alpine cassette player lol. Anything jump out at you?

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Nobody? Reinforces my opinion that nobody likes electrical Except me lol. Can anybody at least tell me where that little plastic piece in the second picture should go?
 
Nobody? Reinforces my opinion that nobody likes electrical Except me lol. Can anybody at least tell me where that little plastic piece in the second picture should go?


That is the heater control light. It mounts on the bottom of the dash kust above the heater lever.
 
Anybody got a pic?
 
have you found a good wiring schematic?


Have you discovered the magical website that @Coolerman has built?
 
have you found a good wiring schematic?


Have you discovered the magical website that @Coolerman has built?
I have a haynes manual but it’s not the most straight forward diagram Ive ever seen. I dont think ive seen the site you speak of.
 
 
@ratpin I see you are new to the site. Ask questions, be patient, expect to be told to go search.

Almost everyone in this section will be helpful in one way or another, if you help yourself.

Do the research.



Welcome! Hopefully you're not getting pounded by the fires or smoke.
 
And in case you haven't tried this yet:

 
Nothing can beat a good wiring schematic, but a very nice visual depiction of a '78 harness that'll be nearly identical to yours can be found here.

x2 for digging through Coolerman's website.

A '78 color schematic done by another Mud member in the past. I can't vouch for it's accuracy but I believe it should be. You can compare the wire colors against Haynes if you find discrepancies.
 

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Most sound electrical advice will start with something like "clean and shine up every ground connection". Additionally, for your rear light issues there's good reason Coolerman, one of the only people that repairs harnesses, doesn't bother with rebuilding rear harnesses. They're usually hacked up and too far gone. The front harness plugs into the rear where it passes through the firewall on the passenger side. You can try shining up those plug connections with a jeweler's file and some de-oxit first, checking for continuity along the way. God speed! And double check the continuity and wear on the brake light switch behind the brake pedal. :beer:
 
Sorry, missed this post when you posted Sunday.
1 - Please eliminate wire nuts on your cruiser! Wire nuts are for houses, not for cars!
2 - This is the heater control illumination light, which mounts under the dash above the accelerator pedal. #17 on this page for 9/72 - 10/82: Page 172 Land Cruiser 40 & 45 Series Dash Parts
3 - Those two bulbs could possible be for the seat belt and brake warning lights mounted by your left knee.
4 - Don't know what those cut wires are for, if you could pull back and show which connector that is may be able to help.
 
Things that are working, then not....
Better hope your fuse block is still under the dash, by the front of the driver's side door.
Find a list of what's on what fuse for that year. Not just the one liner for each, but entire list, including US options.
Every time something stops working, put a test lamp or multi meter on the fuse and make sure you have power at the fuse. Check everything else on that fuse and see if it still works.

And make sure your battery's negative post is connected to chassis (i.e. ground). Clean the terminal, check and clean the cable going into the terminal, check the far end on the frame, make sure it's clean and securely bolted down. Maybe run a second ground.
 
after dinking around with it a bit Im thinking that some of the pull knob contacts had oxidized and were getting inconsistent flow through. After cycling them dozens of times I have gotton almost all accessories to work. I did find that the rear heater motor was actually sitting in a puddle of water/coolant in the little tray it sits in. It would not turn with a direct hot lead so I’m thinking it’s toast. Do most owners find keeping that rear heater beneficial and if so, is it a common part to acquire?

also, i’m thinking I may want to replace the cluster. From what I have gathered on the forum, this was at some point modified by a “Drew”. while I have read many members like his work, I would rate what I am looking at as a bit hacky. see below.

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If you drive your 40 in cold weather or snow, it kinda needs as much help as it can get, in my opinion. So I would keep the rear heater. I got mine used somewhere and it doesn't work great either, but some folks have great working rear heaters.

Make sure your fuses are held tightly and that your fuse block is nice and shiny. It can do wonders for gremlins. And make sure all your ground connections for lights etc. are clean.

Your gauge cluster was modified according to this thread:
 
If you want to get rid of that cluster let me know, I would like it.
Dyno
 
The American flag is not a shop towel.


Good job working through some of the electrical gremlins. I don't know where you are at in Oregon but here in western Montana I really like having the rear heater in the back.
 
after dinking around with it a bit Im thinking that some of the pull knob contacts had oxidized and were getting inconsistent flow through. After cycling them dozens of times I have gotton almost all accessories to work. I did find that the rear heater motor was actually sitting in a puddle of water/coolant in the little tray it sits in. It would not turn with a direct hot lead so I’m thinking it’s toast. Do most owners find keeping that rear heater beneficial and if so, is it a common part to acquire?

also, i’m thinking I may want to replace the cluster. From what I have gathered on the forum, this was at some point modified by a “Drew”. while I have read many members like his work, I would rate what I am looking at as a bit hacky. see below.

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Drew provided the mask and barrel connector for the three aftermarket gauges and possibly some electroluminescent wire for illumination, but that trailer light plug wiring job is a previous owner hack job, not Drew.
 

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