i had the same problem, first i checked all the fuses all were good, then i put on a new gauge, still had the problem, i had to replace the trim sending unit on the right side of the outdrive.
Check all connections too? I had trouble with my 'up' went thru and checked fuses, connections and where the connect at the exhaust housing was pulled apart enough for the down to function but not up!
Frequent problem that is usually a break in the insulation on the wires going to the underwater section of the trim sender, it allows water to get into the sender and short it out. In the first 8 years of this boat I had to replace 4 trim senders for that reason. New senders seem now to have a more flexible insulation, present one is in its 4th season.
Changing it out is a bit of a pain and can only be done with the boat out of the water, I did a write up of how to do it on this forum some time back, a search should find it.
Here is a link, post number 7 http://forums.iboats.com/volvo-pent...umber-my-trim-sending-unit-please-600213.html
