What electrical component is this?

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Apr 10, 2006
Trying to restore some semblance of the stock wiring to a '79 FJ40 that was badly abused. Looked at a Haynes schematic, I don't see this device. What is it please and what should be connected to each of the 3 terminals?

Looks like a horn relay.
that is not a stock item
the poor crimp connectors and where it is mounted is a dead give away
and the wire nut.
Not stock.
Probably a horn relay. Verify the horn works, unplug it and test.
Definitely a mess that you should clean up... Looks like a bunch of bare copper on the wire coming off one of those terminals, probably a disaster waiting to happen.
Will do. Thanks for the responses. Clean up is the plan, you don't know the half of it. The cab is just as bad - wire running everywhere, mystery switches that don't work, etc. Trying to trace each one back to its source, see if I can eliminate. But its difficult and I'm not electrically gifted. How could someone do this to any vehicle much less a Cruiser? Wouldn't it have been easier to replace the factory heater valve? Aaarrgh!

factory a/c? nice
might be better off getting with @Coolerman and get a new harness
For starters....
Get some butt splices, quality ones, with heat shrink, maybe even waterproof ones with glue, a little expensive, but...

And replace all those wire nuts. Wire nuts are fine (I guess, standard practice) in a house, with solid core wires. Don't use them in a car.

And, when tinkering with wires like that, pull the negative terminal off the battery. Save some sparks (and blown fuses or fire).

(love the shut off valve in the heater hose!!!)

And looking back at the first picture.. Is that an alligator clip connected to the coil? The wire nuts are bad enough, you got things attached with alligator clips?

I wanna see more of this wiring!!!:popcorn:
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I think the PO was a building contractor ;) .
And not a good one.
I actually like threads like this. Makes me feel better about my rig 😂.
It's like a bad horror movie, I just can't stop looking!!!

That first picture on post 5:
Right in the center of the picture, that object with clear plastic tubing connected on both ends, is that a fuel filter (and clear plastic tube for fuel line!!!!)?​
And on the top edge, just above the alternator, the black rubber tubing going into something with a metal tube coming out of... What is that?​
And the other thing, on the heater hose between the gate valve on the head?​
I need to see more of this, please, more pictures!!!
Good thing it's a long weekend, you're going to need it!

I'd say best option is to pull the harness out, and look it over... it may be salvageable?
That is some serious PO Wizardry!!!! Got to get rid of the wirenuts, where is the THHN? Waterproof butt splices is one way to go but the better way is to use adhesive lined heat shrink and solder, infinitely more reliable imho. I too love the heater valve, it could have been bigger.:rofl:
Just came in, too dark to continue. Yes, I found Coolerman's list of schematics last night, really appreciate those being there, thank you. It does have factory air and incredibly it works, blows cold air immediately. For the record, I wouldn't use wire nuts on a vehicle, those are all courtesy of the PO. I like the heat shrinkable connectors, haven't tried the ones with solder in them yet. The Sherco brand is my favorite, made in USA and good online pricing. No question solder and heat shrink is also tried and true, I'm still in teardown mode trying to figure out what was done before taking the path to redemptive repair.

We love the responses, my wife and I both had a good laugh. Yes, the clear plastic tubing is the fuel line and the black canister the filter. Just laying there unsecured. The hose section on the alternator with the brass elbow is the coolant circuit for the oil cooler, there's a pipe nipple coming out of the top to connect the loop. The wire reinforced line runs to a temp gauge in the cab. I guess someone thought this was the best way to install it. In the process they undid the fixed metal section and wire tied it to the air cleaner. The white plastic part behind the gate valve is a generic cable actuated valve connected to the pull cable in the cab, apparently that was the first attempt at a fix.

I was going to ask if we're shamed yet but it appears we may have qualified. Just in case, here are a few more images. Note the 3 switches, 2 hanging and 1 fixed, near the base of the steering column. Don't have a clue what they're for, nothing happens when toggled, key on or off. You gotta love the custom jump seat, the canteen makes it. Then there's the receiver hitch mounted 12V winch actuated lift platform. Where's the receiver you ask? It's in the bed secured by a 1 inch bolt punched right through the metal. But it does have a reinforcing plate underneath so I guess that makes it OK. The driver's side of the engine bay looks better than it is, most of the emissions vacuum lines are cracked or fall off their connections. Underneath there are more loose wires. It's a shame the way the body been's cut up, it's remarkably solid. Even the floors and rockers have no more than minimal surface rust.

Thanks for the comments, we look forward to reading them.


The top is not from a 79 and I love the jump seats. There is a whole house of shame on the rear end of this!! Did the PO really tow something with that ball hitch? Glad you and your wife have a sense of humor, it will make this madness more fun.:D
Wow, I'm lost for words. The 12v lift is both amazing and horrifying. The PO is maybe the greatest bush hack mechanic I've ever seen. Definately thinks outside the box.

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