# How to test/debug Datamarine speed and depth gauges?



## tomgee (Nov 30, 2006)

Hi,

I'm a new owner of a 1980 Sabre 28 with Datamarine S100KL knot meter and S200DL depth gauge. Neither instrument works. I don't have any documentation on either the gauges or the transducers, but I'd like to test them out before I repair or replace them.

I have and can get a hold of electriconic test equipment but I don't know what to look for.

What voltage/current should I see from the impeller transducer if someone is spinning it? How about the depth transducer?

Can I apply similar voltages/currents to the gauges to see if they work? If so, what ranges?

Finally, does anyone have or know how to get a hold of the technical specs for these gauges?

Thanks in advance!


----------



## mike dryver (May 13, 2006)

datamarine is still in business. i just checked as i was writing this. you should be able to contact them for info, if not try a marine electronics sales/repair facility in your area. someone may/should have the info. regarding your testing, have you checked/and cleaned your connections. i assume the boat is in the water. not being a wise ass but, you would be suprised at how many times that happens. ( it's a brain fart), anyway that's what i would do! good luck!


----------



## Faster (Sep 13, 2005)

Manufacturers seem reluctant to give out much information of use in troubleshooting... they'd rather you pay them to fix things.

Mike has good basic advice re: checking connections. Do the displays power up at all? if they read zeros then at least you know you're getting the power to them.
The speed impeller should produce some sort of pulse train when spun - but again specs are hard to come by.

As older instruments they may not be worth much, but in a way they are worth what it costs to replace them. Checking with the manufacturer makes sense, they can give you an estimate, or, you could put a cap on what you are willing to spend on repairs - often they will give a bit of a deal if you end up buying new from them after repairs are deemed not worthwhile.


----------



## tomgee (Nov 30, 2006)

Yes, the displays work, but just show 0's.

Just curious, did the technical specs come with the original datamarine documentation?


----------



## mike dryver (May 13, 2006)

iwould imagine they did. i have imi combi instuments on my boat with the same prob. for the mast head and the hull speed. solved hull speed (barnicles stopping wheel from spinning) but mast head is another prob. and i think i will have to rplce whole sys. these are orig. as installed by dealer or what have you in 79. the big prob. seems to be good connections and the senders in my sys. good luck as before


----------



## TSOJOURNER (Dec 16, 1999)

The pervious owner of my boat saved all of the technical manuals right down to the galley fawcett (everything but the sink). All arranged neatly in a 3 inch binder. Instruments are in section 4.

I have the Datamarine manuals for these instruments. Wiring diagrams are shown but not the voltage / current from the displays to the transducers.

I'll take a closer look at it later today and let you know if I find anything. I don't have a scanner, but I can photocopy the info I have and mail it to you if you pm me your address.


----------



## SailorMitch (Nov 18, 2005)

Why not give the DMI folks a shout at this point? They will be the best source for info on how to fix the instruments. http://www.sea-dmi.com/datmar/index.htm


----------



## Bob Matreci (Feb 11, 2017)

Hi Capn,
Do you still have the Datamarine instrument schematics? I want to troubleshoot my sounder - am a retired Elect Engr and consider this a challenge. The service manuals have waveforms photos and adjustment procedures and I have the required test equipment. 

Doesn't make economic sense to not send it to DMI, Inc., or just buy a new one, but I would enjoy tinkering!

Bob Matreci


----------

