California Spec Emissions sub-harness help (1 Viewer)

[Coolerman]

I am refurbishing a 1976 FJ40 California spec main cowl harness. It has a 6 pin emissions connector on the main harness that this sub-harness plugs into.

There are two sub-sub-harnesses that plug into this sub-harness. I do not have these two sub-harnesses so have no idea how long they are. The one that plugs into the three pin connector I do know has the water temp sending unit wire in it.

If you have a 1976 California spec FJ40, have these two sub-harnesses intact, and are willing to provide me with the lengths of each wire, their colors, what they go to and the connector type I will provide you with a $20.00 credit for anything I sell or will build you a new set of these sub-harnesses for your truck.

I appreciate any help with this!

Mark aka Coolerman

 

[iptman]

Think this is the same on a 77 Cali spec? If so I can take a look at mine.

 

[Coolerman]

It may be. I am not an expert on the California spec harnesses. Post any information anyway as I have a lot to learn about the California spec harnesses!

 

[Beachcomber Bernie]

Maybe I can help a little Mark. I’ve got a CA spec ‘76 and battled this myself. Pretty sure that the 2 wire connector on that harness plugs directly into the carb fan temp switch pic below.

For the 3 wire connector: 2 wires run to two temp units under the air rail and the third looks like it connects to the fuel cut solenoid on the carb. That was purely from my own research and had to make that harness myself without example. I’ve passed smog twice but would welcome any correction. Will happily buy a 3 wire harness from you when we figure it out.

 

[iptman]

Here's the sub harness off my 77. Looks to be a different connector going to the carb fan thermistor. The 2 pin connector going to the 2 water temp senders look the same. Let me know if you want info off either of these.

 

[Brian/99uzj100]

Mark,
I have a '76 CA FJ40 and Beachcomber is correct:

The 2 wire connector goes to the carb cooling fan heat sensor

The 3 wire connector goes to the coolant temp. sensor in the head beside the carb (white wire, spade connector) the coolant temp thermo switch for smog located in the head nearer the firewall (white wire, spade connector) and the black (or brown, I'm colorblind) wire goes to the carb fuel solenoid.

Here's some more info from a reproduction CA emissions manual.

I would also be in interested in purchasing both sub-sub harnesses, mine are a little crispy from their location.
Hope this helps,
Cheers,
Brian

 

[Coolerman]

OK so the 2 pin connector on the 1977 uses the "waterproof" connector but is other wise the same as the 1976. I will add that note to my 1977 notes.

Under the metal cover for the actual carb fan temp sensor; is it possible to un-solder the wires from the sensor or are they embedded in goo? Is that a fiberglass sleeve over the wires? If that sensor is still available new, there may not be a need to produce a repair harness.

For the three pin connector: Do the two temp sensors have the same male spade connector? (Meaning the sub-sub harness would use female 6.3mm connectors) is one wire longer than the other? If so by how much? What type of connector does the fuel cut solenoid use? Single pin female?

I appreciate all the info so far!

 

[Beachcomber Bernie]

For the 2 wire connector, it’s easier than that Mark. The carb fan temp switch simply plugs into the 2 wire firewall connector on the main sub-harness of your pic.

The only thing you need to build is the 3 wire sub.
@Brian/99uzj100 is your 3 wire sub original/intact enough to pull and get pics/measurements/spade sizes for Mark?

 

[Brian/99uzj100]

Unfortunately both of the wires for the head sensors have been cut/spliced. The male spade connectors on both sensors are the same size though.
The wire going to the carb solenoid has a fiberglass sleeve and ends in a female barrel connector, the carb solenoid comes stock with a short wire inside a fiberglass sleeve and ends in a male barrel connector.

Like this:

:

 

[Fast Eddy]

My '76 has a 2f from an fj60, so no temp sensors in the head and the sub sub harnesses are long gone. I do have an apparent temp sensor in the egr valve that I connect to one of those wires so the smog guy thinks it's all stock. It has passed a couple times.

My carb fan does work. I'll have to look at the sub harness there. That's the one with the carb relay, right? That works too.

Is there a brake fluid level circuit in a '76?

 

[Beachcomber Bernie]

Is there a brake fluid level circuit in a '76?

No fluid level circuit in a '76.
Thanks for chiming in Ed

 

[Fast Eddy]

No fluid level circuit in a '76.
Thanks for chiming in Ed

What are the two wires lying on the right here? They look like the fluid level wires on my '78.

I was thinking of a different harness, near the vsv, the one above.

The 3-wire sub to the head temp and carb solenoid is looking pretty orig other than the barrel conns. Where's the 3rd wire supposed to go? I can't pull the air cleaner before work, but maybe tomorrow.

 

[Brian/99uzj100]

Eddy, those look like they go to the pressure sensors on a stock tandem master cylinder.
Here's mine:

 

[Fast Eddy]

That's what I meant. My stock master has been replaced with an 80-series master with a fluid level sensor as I have a narrowed 80-series axle in the rear with stock disc brakes.

I have always intended to figure out how to mangle the signal from the fluid level sensor to make the brake light come on in the cab. That's pretty far down my list of things to do at this point.

 

[iptman]

I know you're really looking for the 76 sub harness but figured I'd pull my 77 harnesses off to show the difference. The temp sender harness are each white wires and the thermo switch harness 1 blue, 1 black. It doesn't appear the thermo switch harness is serviceable and since mine actually works I'm not going to pry it open to find out what's in it. It's interesting that the 76 has a 3 wire harness with the 3rd going to the fuel cut solenoid and the 77 doesn't. I wonder what changed so as to not need it. Or I guess they routed it through a different sub harness? Anyway, here's the pic.

 

[Beachcomber Bernie]

@Coolerman ! Got lucky!
Awhile back, I bought a ‘76 harness from a guy and squirreled it away. Today, I pulled off my air cleaner, determined to get you some help and remembered. Sure enough, this was attached to that old harness. The black fuel cut solenoid wire is cut short, but we can figure that one out.

Here, you can see it attached to the temp sensors. The black FCS wire looks to be short about 5” to the male barrel of the FCS sleeved wire attached to the carb. Because of the length of this sub and the ancient bends in the wires, I’m pretty convinced that it originally ran in this orientation and why they have all fried.

Would you like me to ship it to you Mark?

 

[Ackcruisers]

This is a very helpful post. I’m installing a 1976 CA spec harness into a 1976 non USA truck. I’m not installing any of the emissions systems (computer, carb cooling fan etc..). Here is image of my sub harness (I will need to build the sub sub harness).

My questions are as follows:

1. Why are there two coolant temperature sensors as shown in the above post? My truck only has one.

2. For the fuel solenoid wire, can it just connect via barrel connector to my carb. TOYOTA 2F ,H3662 carb Part# 21100-61012

3. Since I am not connecting the emissions computer or carb cooling fan timer/relay, will the temp sensor and fuel cut solenoid items have power to work?

 

[Ackcruisers]

Does anyone have a point of view on my last question #3? Perhaps @Coolerman can weigh in.

3. Since I am not connecting the emissions computer or carb cooling fan timer/relay, will the temp sensor and fuel cut solenoid items have power to work?

After looking at the wiring diagram, there is and LR wire out from 20A heater fuse panel and a YG that connects to water temp sensor on block. According to the Hayes diagram, a separate thermo switch for coolant temp.

The below diagram shows California but not sure how to read this diagram. It appears the circuit powers both the thermo switch for CA emissions as well as the temp sender to the dash.

 

[Beachcomber Bernie]

@Ackcruisers
I believe the temp (gauge) sender is isolated. Pull and bench test the sender unit first with an Ohm meter. If that checks, plug it back in and your gauge should register. If not, test your gauge by running a single wire from your (good) sender to the gauge, bypassing your harness. Confirming that both of these work FIRST is important to answering your question.

Same for your Fuel Cut Solenoid. If your FCS is working, you’ll hear a very distinctive “click” when the ignition is switched to “ON”. I believe it’ll still work without the emissions computer but try it w/wo the EC and see.

 

[Coolerman]

Yes, both will still work without the emissions computer or cooling fan timer/relay installed. The fuel cut solenoid gets power from the key switched ignition circuit through the engine fuse. The water temp sensor circuit gets power from the heater circuit.

What won't work is the carb cooling fan. The carb cooling circuit is separate from the emissions computer so you can have the carb cooling fan work just by plugging in the timer/fan/water temp switch.