When I first had my blower installed along with a Ractronix pump and hot wire kit, we were having fuel pressure problems once the fuel would heat up. Too hard watching the gauge all the time when under boost, so I tried to make a warning light, something that would get my attention even when sideways.
Seemed easy enough. I put a Hobbs switch on the fuel rail and wired it to a light. Didn't work. There was so much pulsing in the fuel rails that there was a wide pressure range where an LED bulb would flicker on and off, and an incandescent bulb would just change brightness. Not terribly useful. I wanted "on or off", not a bunch of "in between".
Needed some kind of damping built into the system.

Not being a "circuit board" type guy, I thought I'd try activating the light through a relay, the idea being that the mechanical relay wouldn't respond fast enough to open and close with the high frequency fuel rail pulsing.
Seems to be working, light comes on steady when pressure drops to 55 psi, and the Hobbs switch can be adjusted to put this point wherever I want. Not enough traction here in Michigan to give it a thorough test though.
The system is still responsive enough to show the momentary pressure drop when mashing the throttle, something the Autometer gauge doesn't show at all.

Four-dollar Bosch 30 amp automotive relay. Could also be hooked to an audible alarm, but right now it's hooked to a LED tail lamp replacement bulb, which is hard to miss!

 

Nice! Pics?

 

Oh, you don't want to see pics!
Right now it's a "proof of concept" hack job powered off the cigarette lighter, with the warning light hanging over the rear view mirror.

Need to make a housing for the bulb, or use a "Pro-Lite", or maybe mount the bulb in the defrost grill next to the heads-up display so it will be reflected in the windshield. That grille pops right out, and plenty of room underneath. The LED array's probably even bright enough to be seen from the ashtray without a problem.
Thoughts on what would work best?

 

You might want to look into the Nexus gauges (on the spendy side). My fuel presssure gauge can be set to change color from blue to red below a certain pressure. Works great.

 

I'd looked into those. Are they bright enough to get your attention in daylight, or do you need to be looking at them?

 

OK, here's a pic taken in the garage. Sorry, it's about 15 degrees here.
You see the head-up display, and on the upper right, the warning light reflected in the windshield. Looks like something you'd notice, but need to check outside in daylight. The 12 LEDs are a little blurry and actually red, hard to get a camera to focus on the windshield.

 

That would DEFINATELY want to make me slow down FAST!

 

How about a vendor to produce an add-on warning light display that projects onto the windshield like above? Low fuel pressure, low oil pressure, over-temp? I'd do it, but too many irons in the fire.

 

 

It is not as noticeable as the one you posted below, that is very noticeable. I do catch the guage changing colors from white to red with my peripheral vision. Having an LED light up in the HUD would be a great way to go.

 

Couple more pictures of the warning light reflection on the windshield, this time in bright sunlight.
The second picture is facing into the sun.......so bright that you can't even make out the heads-up display.





Yeah, the bulb is temporarily stuck to the base of the windshield with a suction cup.
Ain't cuttin' anything up to mount it in the dash till I'm sure everything works as planned.

There's probably room on the windshield for about 20 of these warnings. Could even spell out some text in LEDs like,
"Ain't got no oil pressure, you dumbass!"

 

I have the nexus gauges as well mounted on the piller and have no problem seeing them when they flash...They flash pretty bright but they are pricey