Garmin temp sensor problem.

seabeagle

New member
I have a Garmin 5208 head, gsd22 sounder, and dual beam transom mount transducer with water temp and speed sensor built in. All are up to date with the current firmware. When I first power the system up, the water temp will be accurate approx 57 degrees currently. But, it will slowly rise as high as 185 degrees that I've seen and then wont read at all - gone from the display. I've called Garmin with no luck and swapped out the transducer. The 2nd is worse than the first. Anyone heard of this?
 
I have an older Garmin with an Airmar transducer and it says the water is as high as 101 degrees. I figured it was the sensor in the transducer so now I'm glad I didn't spend the money to replace it. I can't help you any here but I am glad you brought it up and I'll be watching the replies.

I suppose it could be a wiring or connection problem.
 
Many temperature sensors used commercially are RTD types which are typically 100 Ohms resistance at 0 deg. C and the resistance increases with temperature.
That said, it doesn't take very much of a bad connection to add significantly to the 100 Ohm value and that will give you a high reading.

Likewise, variation in the voltage applied to the sensor will give you a false reading.

Connections are the least reliable part of electronics.

Hope this helps.

M
 
I agree with "Grumpy" Go thru the system and clean all of the connections. Use anti corrosion materials for contacts. On the power supply, check size of wires, (resistance increases as connections heat up, and voltage may drop). Also double check grounds--all of the way to the battery terminals.
 
Well, we just spent most of the day on the local lake and the temp did not even appear on the monitor. Checked all connections and voltages. Sonar still works and speed sensor is good. I did notice on the sonar screen that it was showing the voltage at 10.2 volts with ths engine off. I double checked it with the dashboard volt meter and a hand held meter and had 12.4 volts. Not sure why, I guess I'll be calling Garmin tomorrow.
 
Actually 12.4 volts is a bit low. You should be reading 12.6 or 12.7 after running the engine and turning it off. It is possible that there is a connection in the plug to the head unit which is bad or corroded, if it is showing 10.2 volts....I like to check voltages at the very last place down the line I can--such as the pins of the plug or at least post the fuse. The digital volt meter is an essential tool.
 
My Garmin started reading high a year or so ago after working fine for 5 years. The temp reading just keeps getting higher. Yesterday it was up to 146F.

Robbi
 
I would make sure the leads from your transducer are as far away as they can get from any 120 volt that might be part of your shore power systems. Inductance can play a part as over the years insulation can break down. The longer a parallel run the more the larger voltage tries to induce itself into the lower voltage conductor Good steady power direct from a battery (fused) can eliminate voltage spikes and drops which might have an effect if power is shared with other devices. Deteriotating ground connections can do weird things. As others have said check all connections even fuses for corrosion. I would spray the plug and socket where the transducer plugs into the unit with some sort of electrical spray.(BOE) Then plug and unplug repeatedly to make sure that connection the pins is getting a good connection. Just my 2 cents

D.D.
 
If you have a spare battery laying around disconnect the 5208 and the gsd22 and connect them to the spare battery. I don't like the low voltage reading see if it goes away. If the low voltage still is there then clean all the connections. Remember the temperature probe portion connects to the gsd22 and then goes by ethernet to the 5208. If you can find someone that has a gsd22 and is willing to swap as a test put theirs in you system and see what happens. Or you could send your gsd22 to Garmin to test it. I think like others have said above you need to make sure all connections are clean and all grounds are good and the low voltage needs to go away.
 
Update #1

Well, I've talked to the people at Garmin and Airmar and came to the conclusion that the GSD22 is bad. West marine is shipping it to Garmin for repair with 3 days left on the extended warranty. And as for the low voltage on screen, I found that the power cord to the head unit has a bad connection internally. The molded plastic connector was getting hot and with some wiggling it would make the voltage read correct or cut out completely. Must have been bad since the start. Garmin is mailing me a new one for free. I also was reading that there is a GSD24 coming out 3rd quarter this year with a new line of transducers for it. MSRP ~$700.00.

On a side note, my West Marine VHF650 squelch circuit died on me but, West Marine is giving me full credit for it towards a new one. We ordered a Standard Horizon Matrix AIS+ GX2150. Should get it next Wednesday.

I must admit, I'm very happy with the support from West Marine and Garmin so far. Hope this solves the transducer problems. I'll post another update when the parts return.
 
seabeagle":2or9ya8v said:
Update #1

Well, I've talked to the people at Garmin and Airmar and came to the conclusion that the GSD22 is bad. West marine is shipping it to Garmin for repair with 3 days left on the extended warranty. And as for the low voltage on screen, I found that the power cord to the head unit has a bad connection internally. The molded plastic connector was getting hot and with some wiggling it would make the voltage read correct or cut out completely. Must have been bad since the start. Garmin is mailing me a new one for free. I also was reading that there is a GSD24 coming out 3rd quarter this year with a new line of transducers for it. MSRP ~$700.00.

On a side note, my West Marine VHF650 squelch circuit died on me but, West Marine is giving me full credit for it towards a new one. We ordered a Standard Horizon Matrix AIS+ GX2150. Should get it next Wednesday.

I must admit, I'm very happy with the support from West Marine and Garmin so far. Hope this solves the transducer problems. I'll post another update when the parts return.

Hello Seabeagle,

Sorry I'm late to this thread, but I also had a bad power cord on my 5208; my unit would simply go off...sometimes with jostling from a wave, sometimes nothing...then come back on. It was very unsettling. Tracing the power supply seemed to reproduce the symptom with wiggling the power cord at the strain relief just outside the back of the machine. Anyway, I installed a new cord and everything got better. I also noted an increase in the system voltage reading over what I had been seeing with the original cord. I never experienced any temp reading problems.

Fair Seas,

/david
 
Update #2

I received my GSD22 back from West Marine yesterday. It appears to be a brand new one. The case design is ever-so-slightly different from the old one. Hopefully, it is the latest hardware revision with all of the bugs worked out. I tested it on the boat in the driveway and it seems to work fine. The temp sensor was reading correctly at 66.8 degrees and was steady. I'm going to try and get it in the water late Saturday or definately Sunday and see how the depth sounder works.

Also, earlier in the week, I received my replacement power cable for the head unit. Very nice. It is a distinct improvement over the original with a firm fit and secure lock collar. I looked up the part number online and it retails for $30.00. I'm going to try and weasel another one for the radar when I get a chance to call back.

Overall, good experience with Garmin and West Marine. I just wish I did this a year ago.
 
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