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Old 01-22-2013, 07:21 AM   #1
jasonw
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What does this wire go to?

I thought I had labeled every connector when I pulled my engine....but I have one lost wire that I don't know where it goes.

The truck is an 86 305, th350 and the wire is on the main harness under the hood.

Please let me know if you know where this wire should be hooked to.

Jason
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Old 01-25-2013, 05:07 AM   #2
Baralheia
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Re: What does this wire go to?

Oh man. I recognize that connector, but I just got my square back after 8 years, so I can't recall exactly. I think this is for the EGR Bleed Solenoid. Think.

The only other thing I can think of would be the tip-in vacuum switch for the lockup converter on the transmission, but I don't think that's right.
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Old 01-25-2013, 07:16 AM   #3
jasonw
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Re: What does this wire go to?

I know that the transmission lockup has a 4-pin plug and I don't think the trucks in 1986 had an EGR bleed valve...and this plug was super clean compared to all the other engine plugs.

The wire loom was rotten and I rewrapped all the wires with electrical tape...the only thing I can think is that this wire must have not been near the engine. I am going to work on it more this weekend and maybe find where it goes..I am thinking possibly the windshield squirter or something..since I don't remember seeing that wire labeled (unless it is with the headlight wire bundle).

Otherwise...I will be stumped.
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Old 01-25-2013, 08:47 AM   #4
xrcr
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Re: What does this wire go to?

Check out thread on 73-87 wiring diagrams it might help
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Old 01-25-2013, 09:40 AM   #5
superwade57
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Re: What does this wire go to?

Is it your reverse lights? Plugs into tranny
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Old 01-25-2013, 06:36 PM   #6
jasonw
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Re: What does this wire go to?

I was hoping someone would chime in that has more knowledge on these trucks than me....but I think that the th350 has the backup switch in the column.
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Old 01-25-2013, 06:44 PM   #7
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Re: What does this wire go to?

Quote:
Originally Posted by jasonw View Post
I was hoping someone would chime in that has more knowledge on these trucks than me....but I think that the th350 has the backup switch in the column.
There are lots of small changed over the years, but I know that's where MY reverse light switch is located on my 79. That same switch also controls the start-in-gear electrical connections as well.
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Old 01-25-2013, 10:04 PM   #8
Baralheia
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Re: What does this wire go to?

If you've got a Federal emissions truck (not California) and this connector is part of the same harness that connects to the 4-way connector on the THM350C, and to the orange test connector, then I'm almost positive this red connector goes to the EGR Bleed Solenoid. I might be getting the name wrong, but it's a vacuum solenoid over the passenger valve cover that's really close to the EGR valve, and should share a vacuum line with it too. Check either a wiring diagram for your truck or the VECI plate for the vacuum diagram to locate this solenoid.
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Old 01-25-2013, 10:24 PM   #9
hatzie
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Re: What does this wire go to?

Quote:
Originally Posted by xrcr View Post
Check out thread on 73-87 wiring diagrams it might help
The 86 GM year specific diagrams are in my sig. It may take a while to find the plug you're looking for. It's probably in the torque convertor lockup circuit.
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Old 01-26-2013, 09:15 AM   #10
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Re: What does this wire go to?

That "weather-pack" type connector is not found in too may places on 1986 and older. I see them used to connect the GM harness to outsourced components.

The air diverter solenoids, NP transfer case (4wd indicator switch), dual fuel tank switching valve, come to mind.

What are the colors?
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Old 01-27-2013, 10:16 AM   #11
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Re: What does this wire go to?

Quote:
Originally Posted by jasonw View Post
I was hoping someone would chime in that has more knowledge on these trucks than me....but I think that the th350 has the backup switch in the column.
My 86 was original 305 700r4 and I just did a.t56 swap.and recognized the connector type as mine had a reverse switch on the trans. The only guess I have is emissions as stated or maybe a/c. Good luck. There is tons of knowledge here and lots been given to you.they've given you several places in the schematics to check. So is start there and put some leg work in. Sometimes the answers are simple others are not.where does the connector.reach? Maybe that will help narrow results
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