Aftermarket guages?

[fatkid1983]

Does anyone know if the factory digital dash turbo light sending unit runs off of vacuum or boost?

 

[Turbotre]

It's a hobbs switch,it senses boost.

 

[fatkid1983]

See I thought so, I have put an aftermarket boost guage in and I T'd the line to that hobbs switch to the sending unit for the aftermarket boost guage. The problem is it doesn't show any positive pressure. If I get on it and start to build boost it shows-15 as soon as I left of itll start to climb like -14 -13 -12 -11 -9 annd so forth. It doesn't show any positive pressure. Any ideas as to why? Im kinda stumped lol

 

[Turbotre]

Hmmm,that's a puzzler. Are the factory boost lights still working?
If they are,then it must be the aftermarket boost gauge.

 

[fatkid1983]

Yep the factory lights still work great. Its just the aftermarket boost guage thats reading funny

 

[fatkid1983]

I have talked to the company I bought them from and they are sending out replacements to me, hopefully it'll fix it

 

[GNONYX]

Years ago when I got a Boost/Vacuum gauge I was also not sure if the Boost gauge was giving me the correct reading after years of service.
My home air compressor has two air regulator with gauges, one showing the actual air pressure in tank, and the other is a adjustable digital regulator that has a built in gauge.
I remove the hose line from the "Brass Tee" that feeds the Boost/Vacuum gauge, and secure it inline with the adjustable digital regulator hose.
Adjust the digital regulator down to "0" pressure, start the air compressor until it reaches normal rating air pressure. Then turn ignition in the on position, (DO NOT TURN ENGINE OVER).
Since my Boost/Vacuum gauges is digital I can see the Boost display "0"
I slowly open the digital regulator showing 15# and the Boost/Vacuum gauge was showing 17#
It's time for me to get another another Boost/Vacuum gauge
Hope this will help