Instrumenst that just read 000000000

[charlieskipper]

Can anybody suggest diagnostics to find what the problem is. My depth sounder and speed instruments (both simple NASA types) have, since I bought the boat, always shown as 000 when switched on. I have cheked the 'oil' in the through hull depth reader and its fine and I have removed the impeller and checked that it spins (got a bit wet - wrong sized bung at first) but still I have no readings on the screen except zeros when switched on and moving! Where to go next - the wiring looks good but seems very complicated to this novice.

Dave

[ishtar]

There's a page here:

www.nasamarine.com/downloads/downloads.html

where you can get many old manuals for the Nasa stuff. I have the same. I had to replace the impellor, as there was a hairline crack in it, which I didn't at first see. The other problem could be a broken wire - they are very thin inside the sheathing.

Having said that, if both the speed and depth are reading 000, does that not suggest that it is more likely to be the readout, rather than both the log and transducer? I think I'd investigate the screen end first.

[charlieskipper]

Yes that makes sense, thanks

[charlieskipper]

Just to let you know the problem turned out to be both knackered transducer and log with compounding corrosion in connections to the display instruments. This was diagnosed and sorted very reasonably by Roy Luscombe who operates a mobile marine electrics business aound Penarth marina. Both components replaced by Roy who left me to run the cables. I now know how much water there is below the hull - gulp!!!! and how slowly Charlie goes, but happy none the less
Dave