Bombardier 140hp (2007?) gauge problems

[Boatnsteve]

Hi all,
I bought a used boat with a 4 stroke Johson 140 Bombardier on it. Runs great, but at least two gauges don't work; trim and speed. I'm pretty sure the speed gauge worked last year, which was the first year I owned it, but for sure trim gauge didn't work. Tac works fine, not sure about oil and temp.
Question is, what do I do to troubleshoot the problems? Integrated sensors is a new thing for me.
Steve

 

[Boatnsteve]

Just had a chance to check what's what. Tach, fuel, and battery gauges work. Trim and oil don't work. Not sure about speed.
All gauges have power to them.
Checked engine fuses and the two 60 block and two mini fuses all good.
Thanks!
Steve