Wire Identification in the Fuel EVAP system

[evol911]

(I'm cross-posting this from the 2.8l forum with some added info hoping to get a little more traction here in the Help forums. Sorry if this isn't allowed. I'm not sure what else to do.)

I'm trying to figure out an errant wire that was just laying across my engine.

Background: 1984 Ranger Single Cab 2.8l manual transmission 4x4 dual tanks all original emissions equipment in place . No a/c or power windows/ door locks if that even was an option on 1984 models.


I removed my carburetor for a rebuild and noticed a wire laying across the top front of my engine. The wire is a black wire with a yellow stripe, it comes from the battery side of the starter solenoid goes through an 18g fusible link then into a relay then travels through its own separate fabric loom(as opposed to the plastic corrugated loom) which is clipped/attached to the back of the alternator. There are also 2 red wires with orange stripes or dashes in the loom with it. The end of the black/ yellow stripe was just laying on the engine and stops at about the upper water neck. It has what looks like a square female end and no plastic connector over it. One red wire with orange dashes comes from a driver side connector goes through a blue connector at the front of the engine then goes into the fabric loom where it "wye's" into the other red wire which this red wire is the signal into the relay and also goes to the fuel bowl vent solenoid. I can't find these wires in any diagrams I have but I know they deal with the EVAP system/ charcoal canister.

From what I have gathered, power is sent through the red/ orange dashed wire with the key on/ engine running to close the fuel bowl EVAP solenoid (SV- CBV) so vapors don't vent from the carb bowl until the truck is shut off but the other solenoid (CPRV) on the EVAP line is opened to pull vapors from the charcoal canister/ fuel tank during certain conditions as the computer seems fit. But the red wire also sends a signal to the relay to allow power to the black/ yellow stripe wire.

Any ideas? Sorry no pictures right now, I'm away from home for work.

Does anyone have scans of the wiring diagrams from the Chilton manual? I hear they are better than my Haynes book.

 

[franklin2]

Do you have a wire hooked to your electric choke? The carbs on these engines are computer controlled, and have a full 12v electric choke. The choke on these are controlled by the computer, that is why the relay is there. The computer turns the relay on or off to activate the choke, the choke power comes from the relay which is powered by the red wire you mentioned.

When I first got my BII, it was all original but at some time in it's previous life that choke relay had gone bad. Someone had rewired my choke to the white/black on the back of the alternator. Even though that is only about 7 volts when the engine is running, it was enough for the choke to work ok.

 

[evol911]

The choke was hooked up and was working correctly. I have the choke with the stud on it where the wire hooks up which I believe is the correct style choke. I'll trace the wire that was hooked up to my choke and see if it was patched in sometime in the trucks life.

Thanks for the reply!

 

[evol911]

Choke wire is original. I'm guessing the loom would be something to do with an A/C option. Not a single one of the wiring diagrams I have seen show the charcoal canister solenoids or wiring. My best guess is the large wire would have gone to the A/C clutch.

 

[RonD]

Do you have the 1984 Ranger EVTM?

If not I would get one to have, seen here: https://www.ebay.com/itm/234849646136

Ford prints these each year for each model, and sends them out to Ford Shops so they can service/troubleshoot new vehicles that year
Part of the Service Manual set but often sold separately

Lists every wire and it's color, even sub-models and all options in that year

Best part is that they are FREE to use as you can sell it when done with it, just like the person you are buying from is doing

 

[franklin2]

A/C clutch did have a black/yellow hash wire feeding it. But this wire should come from the low pressure switch in the A/C plumbing. If the plumbing is gone it should go to a plug that plugged into the low pressure switch. No relay in the A/C system wiring. I do have the 1984 EVTM

 

[evol911]

Thank you for the heads up on the EVTM! Ordered it and will report back what I find.

 

[evol911]

I'm giving up on trying to figuring out what this wire is. For some reason I had it my head that my truck was a '84, it's not, it's an '83. I was wondering why my truck had those extra "zone vacuum switches" when the EEC-IV manual said they were deleted for 1984 trucks. Well it's because I own a 1983 Ranger. Doh! The 1984 EVTM of course doesn't have any info about the random wires I have in my engine bay. I might try to find a 1983 EVTM sometime down the road but for right now I'm done worrying about it.

Thanks for all the help fellas!!

Anyone want to buy a 1984 EVTM??

 

[franklin2]

I'm giving up on trying to figuring out what this wire is. For some reason I had it my head that my truck was a '84, it's not, it's an '83. I was wondering why my truck had those extra "zone vacuum switches" when the EEC-IV manual said they were deleted for 1984 trucks. Well it's because I own a 1983 Ranger. Doh! The 1984 EVTM of course doesn't have any info about the random wires I have in my engine bay. I might try to find a 1983 EVTM sometime down the road but for right now I'm done worrying about it.

Thanks for all the help fellas!!

Anyone want to buy a 1984 EVTM??

I found out they made two different ones that year, a blue cover one and a green cover EVTM. I have the green one. What color do you have? Apparently there are slight differences in the diagrams in certain areas. You have to watch the Ford literature. It is full of mistakes and typos.

 

[evol911]

I found out they made two different ones that year, a blue cover one and a green cover EVTM. I have the green one. What color do you have? Apparently there are slight differences in the diagrams in certain areas. You have to watch the Ford literature. It is full of mistakes and typos.

I have the a Blue Cover EVTM for 1984. I need the EVTM for a 1983 though.