kawazx636

iTrader: (3)

Managed to steal away some time between my in-laws visiting, working on my brother's apartment building and life simply happening to work on my cab. I pretty much got everything removed from the cab except for the wiring harness.





I was able to get a better assessment of the floor boards with everything out. It looks like I'll be better off replacing the entire floor and tunnel. Honestly, I could get away without doing them, but I'd eventually regret it. Plus I plan on using bedliner on the interior floors and it would look best over some smooth sheet steel without beads like you see in Scouts and old Broncos. I'll 16ga steel for the floors and some 1.5" square stock to replace the seat mount which will double as structural support so I don't have to roll beads.

One of these night I plan on tackling that wiring harness. Hopefully I can keep it installed like it is, cut off the sheathing and slice/pull out everything I don't need anymore (ie: Emissions crap). That way I can "tack" tape it back together while it is in the cab so that I can keep its geometry before I remove it. I'm pretty sure that I can just trace and remove everything that comes out of the Emission Control box which will remove damn near every wire, switch and plug on the passenger side fender wall! Waaaahoo!

Pumpkinyota

With what you are doing already, I'll give you one killer piece of advice: remove the harness intact, replace it with a painless 18 circuit offroad waterproof kit. You will not spend a better 500$.

With age, even jacketed copper gets surface oxidation. Due to the physics of how electricity is carried over a conductor (look up "skin effect" for more info) the surface is the most important current carrying area in a cable. Ergo, old wire doesn't work as well. Also, every connector in your harness is badly oxidized as well.

A new harness will make everything work better. It will start easier, run better, and your lights will be brighter. This is the single best upgrade I have ever made to mine.

I have done the whole conversion, and still have my notes. I haven't taken the time to fully diagram it, but I can put that together if it helps you. Maybe between us we could get another thread rolling

Pumpkinyota

Also, post desmog, the only useful thing coming out of the ECC is the fuel shutoff solenoid. Since you have a weber, you can yank the ECC and all attached.

kawazx636

iTrader: (3)

Thanks for the input Pumpkin. I have considered the idea of doing the painless harness; however, electric and wiring is my one area of weakness. Since my harness is in really good shape, I'm just going to strip out everything that I don't need and reuse it. Once I have it back together and running right, I may go back and redo the wiring with a painless harness. My fear with rewiring it at this point would be troubleshooting once everything is complete. I'm really good with mechanical trouble shooting, but awful with electrical troubleshooting so if I can eliminate that variable I should be better off.

kawazx636

iTrader: (3)

Wellllll.... I pretty much have all the worthless wiring and emissions wiring stripped from the wiring harness. I basically removed the emissions control unit and traced all the wires back to their dead end origins where they used to connect to smog equipment. I got everything wrapped back up after about 5 rolls of electrical tape. Everything seemed to go pretty well except for the starter relay. If anybody has had experience with the wiring of the starter relay, please chime in here. Basically, what I BELIEVE the scenario to be is that there is that the fuel shut off solenoid ran through the starter relay. There are 4 wires going to the starter relay connected by 2 plugs (one is blue and one is black) but none of them seem to run to the starter from what I can discover (I still have some sorting out to do). There is a Black/White wire that runs to the starter (grouped in with the oil idiot light and temperature light) that I should be the start switch to the starter. I'm just not quite sure what to do here or if there are better alternatives to the factory relay set up - Electrical is pretty much my only weakness. Help or advice will be greatly appreciated.

I'm at work right now, but I can post pictures and more information later tonight.

suncomb1

1979-1983 Toyota trucks-Federal did not have a starter relay. I do not have one in my 1983 and I have owned it since new. My motor is a high compression unit and my starter has always worked fine.

83Toyota88

iTrader: (1)

[QUOTE=kawazx636;52119623]Basically, what I BELIEVE the scenario to be is that there is that the fuel shut off solenoid ran through the starter relay. QUOTE]

If you are referring to the cut off solenoid on the factory carb it was controlled by the emissions computer. If you didn't already know that maybe that will help.

kawazx636

iTrader: (3)

83Toyota88, I could be wrong about the fuel shut off solenoid - I'm at work so I'm just going off of memory.

Don, I certainly trust you as a reliable source when it comes to these things; however, there is definitely a relay mounted on the passenger side fender wall and judging by the way the wiring was wrapped and tied in, it certainly looked like it was factory, although the previous owner(s) definitely did some hack jobs on some of the wiring so I can't really be certain. So are you saying that you have single wire from the ignition switch to the starter? I can take and post some pictures tonight to give you a better picture of what I have going on.

kawazx636

iTrader: (3)

This isn't my truck, but here is a shot of the starter relay that I am speaking of:





It has a blue a black plug coming off of it. Thoughts?

suncomb1

The relay you are showing is originally the one for the CMH heater on the carb. Maybe someone changed it for use as a starter relay because it can take high Amps. Original Federal Specification wiring:

B/Y (Small) - Relay Coil - Engine Fuse
B/R - Relay Coil - Computer
Blue - Relay NO Contact - "E" Circuit Ignition Power
B/Y (Large) - Relay NO Contact - CMH Heater on Carb.

I have a B/W wire coming from my ignition switch to the starter Solenoid. The Wire is located in the engine wiring harness on the passenger side. The wire exits the harness near the battery and goes directly down to the starter solenoid.

kawazx636

iTrader: (3)

Thanks Don, that makes perfect sense. I went home during lunch to snap some pictures.

From the blue plug - The blue wire ties into the (+) on the battery. The black/yellow wire apparently went to the CMH (which I removed with the LCE intake plate):


CMH plug (heavy black/yellow wire) from the blue plug coming off of the relay:


From the black plug - the blue/red (Cut) went to the emissions computer. Does the small black/yellow go to the ignition switch?


My next question is what is this that my thumb is point to? It is a blue wire with a red dash. I'm assuming it is some sort of resistor



So I am assuming that I can remove the CMH relay and its wiring since I will no longer have a CMH? Also, I am assuming that the smaller black/yellow wire (going to the black plug in the pictures above) was the feed off of the ignition switch. If that is the case, I will need a feed off of the ignition switch for my additional gauges that I am installing, can I use that? Or is that not a constant feed when the ignition is on?

Pumpkinyota

I'll second Don on this one. You shouldn't need a starter relay either, the amount of amps that the solenoid pulls would be inconsequential. I could throw an amp clamp on mine to test if you like, but I'd venture a guess that it is less than an amp on these trucks. Just bypass that relay, rip it out, and wire it up direct. One more useless thing pulled from your truck!

Pumpkinyota

Yank it.

On the black, yellow wire, never assume with electrical. Do you have a voltmeter or test light? You will want to test and make sure that wire is doing exactly what you want it to first.

You probably have a more convenient ignition switched hot in the cab, as a result of removing the ECC anyhow.

kawazx636

iTrader: (3)

I was mistaken in my recollections from last night (I've got spaghetti brains from all this wiring). I verified when I went home during lunch that the relay was indeed for the CMH and not connected to the starter. My primary concern now is can I use the black/yellow wire that went to the relay as an ignition "on" feed for my gauges? And what is that other resistor and wire in that last pic above?

suncomb1

The small B/Y wire originally went to the ENGINE fuse.
The thing you have your thumb on is a NOISE suppressor and there are several located throughout the engine compartment.
The Blue wire from the "E" circuit of Ignition Switch can be used for an Ignition power source.
The small B/Y from the ENGINE fuse should not be used as an ignition power source because it will not carry enough Amps for anything other then a relay coil +.

kawazx636

iTrader: (3)

I should probably keep that noise suppressor then. So that B/Y wire is only hot when the ignition is on?

suncomb1

The small B/Y wire is only hot when the ignition is on.

The heavy blue wire originally came off the "E" circuit of the ignition switch. Your Blue wire was cut and installed on the battery. Look for the other end of the heavy blue wire under the dash (wire factory splices into the B/Y wire off the ignition switch) and see where it was cut. Install a plug-in type connector and then install additional wires for your gauges from the new connector.

Pumpkinyota

Always test, with a meter or a test light, even if you know what the wire SHOULD be doing. It takes a few seconds, and then you have knowledge, not a guess.

For a test light, you attach the clamp to ground, and touch the probe to the wire with the ignition off, and ensure it does not light up. Then you turn the key to on, and repeat, the light should glow if its hot.

If you don't have a multimeter, I highly recommend buying a cheap one. Get one that is auto ranging, it is easier to read for a newbie.

If you have a multimeter, set it to volts DC, touch one probe to ground (your battery is convenient) and one to the wire. It should read 0, or a few millivolts. Turn the key to on, repeat, it should read from 12 to 14 volts.

Be careful when attaching loads to an existing circuit. It all comes down to how many amps, or how much total power, you can draw down that wire before it gets too hot and the jacket or conductor melt. If you are attaching a new load to an existing circuit, you want to know, if possible, how much load you are adding, and how much is already on the circuit.

In your case, you want to have an idea of how much your new gauges will draw. They should all have a rating, look for "amps" or "milliamperes" on the spec. If you like, post your gauges and brands, and I'll look them up for you.

Once you know this, you can asses the size of the wire, and be sure that it is large enough to carry your load.

I don't expect high draw out of gauges, and if memory serves, I think the ECC used to be powered by that engine fuse, Maybe Don could check me on that. It is probably ok, but you probably have more correct options inside the cab, on smaller fuses.

kawazx636

iTrader: (3)

Thanks for the input and help guys, much appreciated. The gauges were just a thought in the event that I could use a wire that is already there. I was more concerned about figuring out what the relay for and if it was ok to yank. I plan on installing a fused power block to power accessories and such. Probably two - one tied into the ignition and one constant. Not quite too sure how I'm going to do the gauges yet.

kawazx636

iTrader: (3)

And I do have a multimeter and I would test it, but I yanked the steering column with everything fully assembled on it so I don't have the ignition attached to turn for power... In retrospect, I probably should have left that on while doing this, but it would have been in the way a lot. I guess I just have to cross my fingers and hope that everything works when I crank it