Ok Gang...

I've seen a bunch of you wondering about needle valves... Well here I'm going to explain the reason and why needle valves should be used on all fuel pressure gauges including electric gauges.

Now first thing first is why do we need a needle valve? Well the needle valve is a adjustable damper for the fuel flow. It prevents harsh or water hammer pulses from reaching the gauge or sender.

What is water hammer?

http://en.wikipedia.org/wiki/Water_hammer

Here is what the pulse looks like...

But now figure that is pulse open and close at half the RPM's but for 6 cylinder. This pulsation with eventually wear out or eat the gears out of mechanical gauge or electric senders.

So here is a quick video of proper set needle valve...

http-~~-//www.youtube.com/watch?v=M33ZCc8b-7Q

I figured it out with a little help....on my truck the brown wire comin out of the dimmer switch dims the factory gaugesi tapped in there! Dripley, you were refering to a tapafuse....napa had them when i went to get some stakons...thanks for all the help

I have an add a fuse, but this one just fits in the fuse slot and the fuse goes right back in the slot.