700R4 question

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BadBowtie

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Per a YouTube search, I am currently working on installing a "vacuum delay valve" into our all stock 1984 Silverado 5.0L TH350C truck. These raise the required vacuum pull before allowing the lock-up torque convertor function to occur.
 

Pullit

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Also get a cruise control brake light switch and wire it through the normally closed contacts. That way if you forget to turn it off it will unlock when you apply the brakes.
 

Ricko1966

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Also get a cruise control brake light switch and wire it through the normally closed contacts. That way if you forget to turn it off it will unlock when you apply the brakes.
Or just use the existing brake light switch to trigger a relay which would interrupt the circuit,I can draw you a diagram if necessary,but if you wire it through a 4th gear pressure switch there is nothing to remember, or forget. 4th gear it locks,any other gear it is unlocked.
 

squaredeal91

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I'm late to the party. I have a lockup switch on the dash in my 78 and I turn it on in 2nd and turn it off when slowing to a stop. I do want to eventually wire it with pressure switches but it works okay for what it is. I was driving without and had to do something.
 

Ricko1966

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I'm late to the party. I have a lockup switch on the dash in my 78 and I turn it on in 2nd and turn it off when slowing to a stop. I do want to eventually wire it with pressure switches but it works okay for what it is. I was driving without and had to do something.
It's just 1 pressure switch,and it's already in your valve body . It's a very simple circuit, 1 power wire to the transmission, 4th gear switch opens and closes power to the solenoid. You just use 4th gear switch to turn the solenoid on and off. Think of the 4th gear switch as the toggle switch.
 
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Matt69olds

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It's just 1 pressure switch,and it's already in your valve body . It's a very simple circuit, 1 power wire to the transmission, 4th gear switch opens and closes power to the solenoid. You just use 4th gear switch to turn the solenoid on and off. Think of the 4th gear switch as the toggle switch.

Not all pressure switches work the same. Some are normally open (grounds when pressurized) others normally closed (grounded UNTIL pressurized) either can be made to work, you just need to be creative with the wiring methods.
 

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