I have 3 guage isspro setup. Lately the tranny guage has been flakey bouncing up and down on its own. Sometimes it starts out at 130 as 0 when i start the truck up, then it goes back to normal if it hits a bump. I reset the wires going to the amplifier box and also reset the connector at the tranny sensor. I did check the ground as well. all looks good. sometimes it will be good fro a day or so then it goes back to bouncing around. Any ideas? thanks jeff

 

I would give Isspro a call if you have checked all connections.

 

I had the same thing happin with my coolant temp, In my case it ended up being the plug that goes into the sending unit..Usally, when they start bouncing around, it will be a ground issue..