Trans overheating or bad gauge?

[Dahlilama]

Hey guys... New to the forum and hope u can help me!! Let's get to it since I NEED my truck Monday and it's almost Sunday already! This has been covered but my problem seems to differ a little bit from everyone else. Installed auto meter gauges on my 99 late model 7.3 powerstroke f350. It's a one wire sensor. Wired it up. Grounded under dash. Gauge just keeps climbing and climbing until 250 which is the max then goes past that. I used a jumper wire to try grounding it to the chassis and or the trans. No effect. I took a temp gun and there is NO part of my trans that read over 118 while the gauge said 250+. my trans at this time is warm when u put ur hand on it...just warm....def not hot!!! One cooler line feels slightly warmer then the other but just barely. The bypass tube is just as warm as the other lines but NOT warmer. Gauges have been in for only a few days. So what do u think? Is the trans really that hot? It's about 20 degrees outside. Truck and trans have 260,000 miles. Auto meter says it's the ground but I tried that. Doing the bypass line and cooler flush tomorrow to be sure. Prior to the gauge install I ran this truck 70 miles one way to the Bronx at 70 mph with two JAMMED rear calipers(oops...bet that but stress on that trans)I just wanna know if u think it's safe to drive around. I'd figure if it just feels slightly warm there is no way it's at 250+ !! I feel no slipping and the fluid is nice and pink. Plead help

[smokenstroke]

No way its over 250 and you can touch the pan

[Dahlilama]

thanks...thats what i thought and what i was told but its so hard to believe beause the gauge slowly climbs to that temp. it seems most ppl that have a bad ground or guage it jumps around or dorsnt move. i did also try touching the oil pan as a comparison since the truck is running in the 180 range and boy that oil pan was hot. its just nerve racking with a gauge a foot from my face telling me my tranny is over heating. thanks again for your help