That year did not have 1. No need for 1 because it is computer controled
It is on the passenger side of the transmission towards the back of it. It will have a vacuum hose hooked to it. There will be a small bracket with 1 bolt that holds it in the transmission. Do not loose the small pin that is inside of the transmission when you remove the modulator valve. You will loose some trans. fluid.
That transmission is electronic controlled. No need for a modulator valve.
That year transmission did not use 1
That year model did not have a modulator valve on the transmission.
If your transmission has a modulator it is on the side of the trans and it has a nipple on it for the vaccum line. I you. Mark
The vacuum modulator on a 1989 Chevy K-1500 4wd 5.7 is underneath the transmission. It can be reached from under the car.
On the back of the trans. There should be a vacuum line running to it.
If your speaking of the vacuum modulator for the transmission, they no longer use them on the transmissions with overdrive and electronics. The powerglide, turbo 350 and turbo 400 used to use them.
Defective modulator valve.
The factory transmission that belongs in that 94 model did not use are have a modulator valve. But to answer your question the line goes to any intake vacuum source. That year truck should have the 4L60E transmission in it.