Depth gauge not reading, even with a new triducer

[cstang92]

We have a 2008 RZ4. The depth gauge always reads 997 feet (temp and speed work fine) so we bought a new triducer and the depth still reads the same. My only other bit of info that might help is that when I removed all 3 batteries to charge them ahead of this summers boating season and started the boat back up in the spring, the depth gauge seemed to read correctly but as soon as we turned the boat off, it went back to 997ft. Is this a wiring issue? Any ideas or suggestions?

Thanks in advance.

[mikemcclain8]

In this discussion, they mention the thru hull paddle wheel being used for the speed, temp, and depth. May check that:

http://www.wakeworld.com/forum/showthread.php?t=781826

[isaac]

Is this an analog gauge? Is 997 the reading one would get with nearly full needle deflection… and it reads opposite this with the power turned off? Could be the other way around.

if so, the gauge works by reacting to the electrical resistance between the sense post (probably on the left when looking at the rear of the gauge), and ground (probably in the center of the gauge)

First check that you have solid ground and power connections to the gauge. There should be three posts somewhat in a line across the backside of the gauge. Power is probably on the right of the backside of the gauge, and ground is in the center. There may be a connection “up high” and that’s for the gauge lighting.

Full deflection happens when the gauge sense post and ground are shorted together. Minimal deflection happens when there is no connection on the sense post. Mid gauge readings happen when the resistance between sense and ground posts is likely somewhere between 5 ohms and 200 ohms. You can test this by disconnecting the sense lead (don’t let it touch anything), and alternately shorting the gauge sense post to ground and then removing the short. The gauge should react accordingly. If so, the gauge is most likely fine.

whatever you do….. don’t let 12v touch the gauge’s sense post as you will ruin it.

After reconnecting the sense lead, you can see if the gauge is getting readings from “the system” by putting a DC voltmeter between sense and ground… you’ll probably see something like 6 volts at zero depth and decreasing voltage as the real depth increases. If you don’t see this, then the problem is not the gauge. In fact, it may make sense to try this first without disconnecting anything.

BTW, you can test the TAPS analog gauge the same way, using the trim button instead of depth

[isaac]

On reflection, it’s maybe a digital gauge like a Faria Commander. In that case “never mind”!

[cstang92]

It is a digital gauge but gives me a few things to think about. The gauges are Medallion (see attached picture). Also worth noting, it reads 997ft on the center digital screen but also on the little digital screen inset within the rpm gauge.

Appreciate the feedback everyone - keep it coming!

[freeheel4life]

I couldn't tell you how the ducer communicated with the gauge in 08...but those were early years of CAN bus AFAIK. On the boat side harness/plug what are the wire colors?? If there's a blue, white, purple and black then it's surely CAN. If so there's at least some voltages worth checking....

[KoolAid]

If you purchased it through a dealer, there is an issue with the triducer. Airmar is currently reflashing them to work with older boats. For some reason the later units were flashed with the later NEMA2000 PGN's only and did not have the historical PGN's. Give us a few weeks and the new ones will be available. Dealer can request a replacement and we will swap it out with the correct unit.