ok my truck has been acting up when i was driving i noticed my rpm guage stopped working then when i cut it off the truck wouldnt start till i messed with the connections. i also noticed the reason is my airdog isnt cutting on when this happens but when i get in the truck and turn the key i hear the pump for 1 sec like normal then i test it by bumping it and it wont run but when it does it will run fine till i see my rpm gauge go to 0 then i no i have a problem and i have changed the connections on air dog 150 and no help so please help thanks.

 

crank sensor most likely. thats what generates the tach signal

 

would it mess with my fuel pump thanks

 

When my crank sensor was going out it would kill the whole truck driving down the road. Your pump is wired into your ignition and if the crank sensor is messing up it wont let truck fire. The sensor is behind the starter. Unbolt the starter and drop it down and it real easy. Takes about 30 min. I took mine to autozone and had them read the codes. It was kicking one out for the crank sensor. Too bad they told me the cam sensor. Spent 1.5 hrs trying to swap a cam sensor for no good reason. Oh well, atleast the truck got 2 sensors replaced in a day