Thread: Why is my boost gauge only reading vacuum and no boost?

You have a vacuum leak somewhere. Check again.

put supercharger belt back on....


nah i dont know. is it taped into the right place??

^^pretty sure that is the line off the MAP sensor underneath the EVAP purge lines in the back behind the blower.

Yeah mine is tied in right in front of the map.

Yeah mine is doing the same thing but I have a 05 GTP, I thought you just had to stick it in that hole above the supercharger?

nope, that only sees vacuum. find a source after the blower.

what line? any pics?

from the MAP sensor on the back of the supercharger...it has a big white plug in it. Can't miss it...T off of that line.

Ok I was able to do it. I found another line infrot of the supercharger that I was able to splice into. It works? shows vaccume and boost fine. How much boost should I be making?

Also how do you wire it so that the gauge can light up?

5-10 psi, idk because your modded. A stock GTP is around 7-8 psi.

With your flow mods and such it will cut down on boost PSI, but you still get the power because it flows better.

Splice the wire into a wire that always gets power when the key is on or buy a TAP A FUSE or ADD A FUSE, thing at a local auto store and use that on you radio fuse.

Originally Posted by Louie3

Also how do you wire it so that the gauge can light up?

Not being a douche, but you might want to have a buddy with some experience help you. The directions tell you how to light it up. One wire to ground, one to the light circuit.

Originally Posted by Fivefingerdeathpunch

5-10 psi, idk because your modded. A stock GTP is around 7-8 psi.

With your flow mods and such it will cut down on boost PSI, but you still get the power because it flows better.

Splice the wire into a wire that always gets power when the key is on or buy a TAP A FUSE or ADD A FUSE, thing at a local auto store and use that on you radio fuse.

I'm getting around 10 psi :-)

This weekend I'm going to tap it in so that when the lights turn on at night the gauge will also

Originally Posted by BillBoost37

Not being a douche, but you might want to have a buddy with some experience help you. The directions tell you how to light it up. One wire to ground, one to the light circuit.

Its cool man I just thought maybe there would be a wiring kit for it or something thats more of what I wanted to know. I've done wiring on cars but never as new as my GTP