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"electrical plug" on 700 trans

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bryguy00b

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\"electrical plug\" on 700 trans

on the 700 from my blazer (1984) my dad says there an electrical plug on the side of it..and he doesnt now what its for...he was wondering cause hes been thing of putting the 700/208 in his 79..now does anyone know what this plug is for? TV cable maybe?? and what would he need ot do to make the 700 work in his 79?
 
Re: \"electrical plug\" on 700 trans

That plug is for the OD torque converter lock-up. Painless Wiring makes a kit to allow the use of a 700R4 in an older vehicle. Check Summit or Jegs...around $125 IIRC. /forums/images/graemlins/thumb.gif
 
Re: \"electrical plug\" on 700 trans

If I were you, I'd pull the wiring for the TCC out of the '84, along with the instrument cluster (or just swap to a later speedo in his cluster) and call it good.

The wiring is no more complex than any aftermarket setup, save for the VSS, which means lockup is also governed by a minimum speed.

I personally wouldn't pay much for a system that is on the majority of 700R4 equipped trucks, and works great.
 
Re: \"electrical plug\" on 700 trans

sweet..thats a much more atractive price!! now all i need to do is convince my freind that he doesnt want this tranny to put in his blazer so i can put it in my dads truck!
 
Re: \"electrical plug\" on 700 trans

You should be able to make a switch yourself. It’s just a 12v power source and a ground. Once a sensor(s) receive(s) input within its specified parameters, in this case vehicle speed and drive gear, it completes the ground and locks up the converter. If you want total control of your tranny you can rig up a switch and control lockup manually. Also, if you are getting the tranny rebuilt, you can bypass the automatic electric lockup and make it hydraulic lockup quite easily. There are pros and cons to all three ways. A good tranny mechanic can fill you in on cost and feasibility.
 
Re: \"electrical plug\" on 700 trans

the lock up has nothing to do with vss. the power is routed through the brake light switch and is controlled by a vaccum operated switch on the fire wall. if you have four wheel the power source is derived from the tranfer case though a switch on the brake pedel.
 
Re: \"electrical plug\" on 700 trans

Lockup has everything to do with vehicle speed. How it determines that speed, I don't know. I'm sure it varies. Whether it determines it based on hydraulic pressure inside the tranny or some other elctro-mechnical swith, I'm not sure. I didn't say anything about the Vechicle Speed Sensor. I suppose the brake pedal switch you are referring to is one of the mechanisms that disengage lock up.
 
Re: \"electrical plug\" on 700 trans

look at your factory manual, it has nothing to do with vss. it has to do with the trtans being in fourth or over drive. the trans will not lock if in fourwheel or the brakes are applied. the engine vaccum has to be at a stedy level for lockup to occur in overdrive. loss of vaccum will open the switch on firewall.
 
Re: \"electrical plug\" on 700 trans

[ QUOTE ]
the lock up has nothing to do with vss.

[/ QUOTE ]

You might think about reviewing whatever TCC wiring knowledge you have. Even 700R4 trucks without cruise control use VSS. There is no reason to use VSS except for ECM systems, and converter lockup.

How do you think GM governed the minimum speed at which lockup occurs so precisely?
 
Re: \"electrical plug\" on 700 trans

the 700r4 has to be in overdrive for lock up to occur unless you have modified it with a switch to lockup in other gears. with or with out cruise has no bearing on it. the 87 and up are controled by the ecm. 86 and lower are not.
 
Re: \"electrical plug\" on 700 trans

Dorian, you have always been a wealth of knowledge, but... The lockup may depend on vehicle speed, but not the VSS specifically. Why do I say that? Pre-ECM rigs don't have a VSS. My 85 is non-computer controlled and has lockup with the VSS. My 81 also doesn't use the VSS. I am not saying that the lockup does not relate to vehicle speed in some fashion, but it certainly isn't via the VSS on pre-ECM rigs.
 
Re: \"electrical plug\" on 700 trans

Unfortunately I don't know where I put the couple of truck TCC harnesses I pulled to retrofit to another vehicle, or I'd go double check.

Anyone else here have that setup out of the truck, and can confirm that the wiring does pass through the module over the gas pedal? (I'm confident it does, but since others think differently...)

What tranny is in your '81?

Wwith 100% certainty though, I can tell you non-ecm rigs DID get VSS. I had an '83 K5 (federal emissions) and VSS was right where it should have been.
 
Re: \"electrical plug\" on 700 trans

Not trying to stir up any dispute, but got to thinking about this again last night.

Now I've messed with both the 700's and 200's, but it's been a couple of years, so hopefully I don't mix them up.

The 700 can and does in some applications, use a pressure switch (like 3rd and 4 gear switches). All of the TCC harnesses (inside the tranny) that are setup for this, use two wires for the solenoid, and one or two more wires depending on how many switches there are. None of the additional wires are hooked into the TCC wiring inside the tranny.

With those switches in place, what "interprets" the open/closed aspect of them? Obviously that could be tied into another part of the entire TCC circuit, but where?

Wish I could remember where those harnesses I have are...
 
Re: \"electrical plug\" on 700 trans

Dorian
not trying to start a war. the two wire setup has the 3-4 interrupt switch wired in the tran. its function is to unlock the converter in forced down shift. the three wire setups do the grounding of the circuts with the ecm. been researching this real hard as i am converting my 85 to 90 tbi. spent many hours lately looking at the 85 verses the 90 wiring to the 700r4.again sorry to come across so strong.
 
Re: \"electrical plug\" on 700 trans

Dorian
not trying to start a war. the two wire setup has the 3-4 interrupt switch wired in the tran. its function is to unlock the converter in forced down shift. the three wire setups do the grounding of the circuts with the ecm. been researching this real hard as i am converting my 85 to 90 tbi. spent many hours lately looking at the 85 verses the 90 wiring to the 700r4.again sorry to come across so strong.
 
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