73-87chevytrucks.com

73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: peckaldee on March 27, 2013, 08:14:24 pm

Title: 700r4 Mystery plug help
Post by: peckaldee on March 27, 2013, 08:14:24 pm
I have a plug coming from the transmission that has a yellow wire and a green wire going into a red connector with two molded round male connectors.  Not sure where it plugs in to.

To clear that up....a harness coming out of the tranny.  It Y's off just over the bellhousing and one side has two plugs that I have already connected to the truck.  The other with the red connector with the Siamese round male parts is what I'm confused about.

Any help is greatly appreciated.

Trying to find a picture on the internet of the plug.

Tried to attach a photo of what I found.  The plug in photo is black but its the same as my red one.



Title: Re: 700r4 Mystery plug help
Post by: winky on March 27, 2013, 08:38:02 pm
Is it near the rear of the trans? And is it 4x4 or 2wd might be for the speedo
Title: Re: 700r4 Mystery plug help
Post by: peckaldee on March 27, 2013, 08:51:30 pm
The other end is plugged into the 4 pin connector on the tranmission.  Speedo is mechanical.  In  86 2wd truck.
Title: Re: 700r4 Mystery plug help
Post by: winky on March 27, 2013, 08:57:33 pm
4 pin on the side? Plugs in pushing down? Not actually in the side?
Title: Re: 700r4 Mystery plug help
Post by: peckaldee on March 27, 2013, 09:05:05 pm
Yes, it plugs straight down.  The only wires on the tranny.  The other end is the problem.
Title: Re: 700r4 Mystery plug help
Post by: winky on March 27, 2013, 09:06:23 pm
I believe its for electric kick down? I was told that one time. I never hooked mine up
Title: Re: 700r4 Mystery plug help
Post by: peckaldee on March 27, 2013, 10:04:25 pm
Still need to know about where on the truck it plugs to.  I'm think know it might be somewhere on the lines going down and back to the rear lights from the firewall but not sure.
Title: Re: 700r4 Mystery plug help
Post by: Fairlane514 on March 28, 2013, 07:42:26 am
Just a guess.......neutral safety switch.......to keep it from starting in gear.
Title: Re: 700r4 Mystery plug help
Post by: Twin_Turbo on March 28, 2013, 06:20:06 pm
Is it this, coming out the firewall next to the booster? Ignore the weatherpack on the end, I added that. These are for the level sender signal and switching valve

(http://www.vettemod.com/forum/imagehosting/2507b283fd2ffa.jpg)
Title: Re: 700r4 Mystery plug help
Post by: peckaldee on March 28, 2013, 07:39:23 pm
Not sure where you are pointing to TwinTurbo.
Title: Re: 700r4 Mystery plug help
Post by: Twin_Turbo on March 28, 2013, 08:18:57 pm
rubber plug off firewall, short length of wires, another rubber connector w/ another short section and a weatherpack on the end. Inboared side, next to brake booster hanging down on the frame
Title: Re: 700r4 Mystery plug help
Post by: Kriegen on March 28, 2013, 11:45:38 pm
The two prong plug is actually for your VSS (Vehicle Speed Sensor, I think).  Anyway, it is for transmissions that have the magnetic speed sensor ring in the tail shaft.

The four prong plug is for the TCC (Torque Converter Connector, I think)  It is supposed to be wired up to lock up your torque converter in OD gear for better gas mileage I think. 

I currently am having issues with my four prong wiring.  Mine was smashed and the wires are faded to where I can't tell which went where. 
So I will watch this post to see if anyone else knows something more.
Title: Re: 700r4 Mystery plug help
Post by: peckaldee on March 31, 2013, 10:29:29 am
So I can leave this unplugged?  Is this a case of the harness being universal?  My truck has a mechanical speedo and the pic TwinTurbo has shown pointing to the wires coming out of the firewall are where my throttle cable are at And not the connector for this plug.
Title: Re: 700r4 Mystery plug help
Post by: winky on March 31, 2013, 09:27:26 pm
So I can leave this unplugged?  Is this a case of the harness being universal?  My truck has a mechanical speedo and the pic TwinTurbo has shown pointing to the wires coming out of the firewall are where my throttle cable are at And not the connector for this plug.
never hooked mine up and it seems to do fine. Just drive it around town and in mud though.