riddle me this; ISSPRO egt gauge problem

[austin18]

ok so i have a 2000 F-350 7.3L with a 6spd. i bought a set of used isspro ev2 gauges from a buddy of mine. everything worked fine while in his truck, however the wiring was basically ripped out of his truck. we rewired the entire boost gauge and it works perfectly. The egt wiring was a bit past gone so i called isspro and ordered a brand new harness from the probe connector to the gauge it's self, well i installed the probe into the lower section of the driver's exhaust manifold. ran the wires from there up to my pod and hooked everything up. turn the key on and the gauge falls to the bottom then jumps up to like 4 and then ticks down slowly, when i start the truck the gauge goes completely to the other side and back to about 100. then it just stays there, everyonce in awhile it'll jump to about 300 then back down randomly. lights come on and i know it is wired correctly. so what do you guys think?

[03machstock]

I would contact Isspro personally.