Where do I tap into the fuel system for a fuel pressure gauge? Do I unscrew the bleeder valve or whatever it is called at the front drivers side fuel rail and install the sending unit or can I tap into it where the gold colored allen head type screw is at the very front of the fuel rail directly behind the alt? Is the bleeder valve a 1/4" or 1/8" hole?

 

I unscrewed the Schrader valve and put mine there. You might want to get some adapters including a T if you want to retain the Schrader valve for easy pressure relief or using a mechanical gauge.

See this thread for the fittings: https://www.performancetrucks.net/fo...light=schrader

 

Schrader valve, I knew that but couldn't remember the name. I was wondering about an adapter, did you get one? I guess I could always relieve the pressure by slowly unscrewing the sending unit with a rag wrapped around to absorb the gas. I was also told not to use anything on the threads, just screw the sending unit in. Any TQ value for that or is it just until "tight"? Fuel leaks are bad

 

It's standard 1/8" pipe thread. The sending unit will go right there nicely.

 

Either put it there or run a steel braided line and hide it like I did

 

I haven't gotten around to ordering the adapters. I was in a hurry to get the gauges working and now it doesn't seem quite so urgent. Too busy spending money on the bigger stuff. I was suprised at how tight the Schrader valve was when I removed it. I just screwed the sender in until it was reasonably tight. When I unscrewed the valve from the fuel rail it looked like there was some pipe sealant on it so I carefully put a little only on the outer threads of the sender. Didn't want any getting inside the fuel rail. Don't know if you need anything with those threads. I did watch for any leaks immediately on starting it up though. No problems.

 

I'm going to go run the wires now and hopefully install the sending unit this evening. I'll post a pic and tell you if I blow anything up.

 

Got everything installed. PITA! Finally figured out I didn't have a good ground and thats why the meter was pegged at 100psi and wouldn't move. The needle does sweep around on start-up but that may be normal.

New problem though: If I get in and turn on the headlights I get nothing on the dash or radio. The radio is playing I just can't see anything. When I turn off the headlightslights everything lights back up for noraml day driving. The funny thing is if I roll the dimmer all the way to where it clicks all the cabin lights come on as expected but the dash/radio light up as well?? Is there a fuse specifically for the dimmer? The dimmer doesn't work basically unless you roll it all the way up and click everything on. So I can't drive at night (and see the dash) unless I turn the inside lights on. I'm lost on this one.

 

Where did you connect to for power to the gauge light. You can't connect to the dimmer switch as that is just connected to the BCM via the databus. It is not directly connected to any lights. I think that I connected mine to the wire going to one of the lights on the back of the switches. The gauge itself should be powered off of one of the ignition wires as per the instructions(hot in start/run or run) I believe.

 

I connected this gauge to the same wires as my boost guage which has worked fine for months. The lighting issue happened before I ever hooked up the fuel gauge, so I don't think they are related. I was thinking I blew a fuse when I disconnected/reconnected the battery or something. The dimmer is the only thing that quit working. I can still turn the daytime running lights on and off with the button (4 quick pushes) and the dimmer will turn everything on if turned all the way up, just no dash lights when I turn on the actual headlights and no dimming with the wheel. Maybe something in the dimmer switch just gave out from me moving it around?