Connecting Garmin B175H to TZT3

[LowTide]

I previously had a Garmin system installed, including a B175H transducer. I expected that the B175H would also be compatible with the new TZT3 16" unit I installed. I cut off the Garmin connector, cut the Furuno 12-10 pin adapter cable, spliced the wires and connected the transducer to the Furuno pigtail. I spliced each wire, color for color. There are the same number of wires in each cable, and the colors are the same, so I matched blue to blue, white to white, etc., and the splices are neat and solid. I also understand that the B175 units are now offered in 'mix & match' fashion where the same transducer can be used on 'any' brand system simply by swapping out the terminating connector pigtail, reassuring my belief that this 'should' work.

The boat is still out of the water, but a few things make me think my installation is not Kosher. On the up side, the transducer does seem to 'work'. When I power it on (only for about 15 seconds at any time to prevent damage), I can see a return that makes sense given the situation of being out of the water. On the down side, I expected the TZT3 to recognize the transducer via XID--this didn't happen, I had to select the transducer model in the setup menu. More bad news, I am not seeing any sea surface temperature reading on the TZT3. I have confirmed using a multimeter that the thermistor in the B175H is working, with a resistance right around 10kohm. I have confirmed that the SST source is set to the TZT3 unit the B175H is connected to. The XID feature worked fine with the Garmin system, although that is not easy to check with a multimeter like the thermistor is (or is it?).

What am I doing wrong?

 

[TheReaper]

The 12-10pin adapter cable is only designed to be used for that purpose. When wiring in the single frequency B175H, the 12-pin pigtail cable is required. The part number is TZ3-12P-PGT. I've attached the wiring diagram for this cable.

 

[LowTide]

I can't imagine why Furuno would use the standard transducer wire colors in this cable and then mix up their functions, but they did. Fortunately I was able to find a schematic for the 10p/12p adapter and determine the correct connections, shown below, and now the transducer, including temperature & XID, is working correctly.

B175H cable-->10p/12p adapter cable
Black-->Blue
Blue-->Black
Inner Shield-->Inner Shield
Outer Shield-->Outer Shield
White-->Red
Orange-->Green
Brown-->White

Cut Red & Green in B175H cable
Cut Brown & Orange in 10p/12p adapter cable

 

[Johnny Electron]

So this is the information is how to interface a Garmin B175H to a TZT3? Thanks for sharing that because I am sure others will find it helpful.

 

[Bill106]

Question for the experts. I am having an issue with a TZT12F installation with a pair of B175's, L and H using the Mix-N-Match cabling. The Mix-N-Match for Furuno's is only available in a 10 pin configuration so both final connections are made using the 10-12 pin pigtail adapter cables supplied with the units. I swapped the 10-12 pin adapter cables also, to no avail.

I have the B175H connected to one MFD and it appears to be working, albeit suffering from some hull boundary turbulence issues.

The B175L is connected to the second TZT12F, using the special low frequency only Mix-N-Match adapter cable, and then the 10-12 pin adapter cable. The MFD correctly recognizes the ducer as a B175L and is receiving correct temp readings but I'm getting exactly zilch on the actual sonar readings, at all settings. Swapping ducers between machines yields the same results on each, B175H working, B175L NADA.

Thinking I may have a DOA ducer I tested it with my TDT1000 and to my surprise both ducers pass with flying colors! The TDT1000 is connected directly to the Mix-N-Match cable so I could not verify the low frequency adapter pigtail and at this point it's the only suspect I can come up with. I have done dual B175's to DUal MFD's before (on Quitsa's installation!) so I know the general concept should work but I'm not sure about the Mix-N-Match combo with the 10-12 pin cables. Do I have a dud low frequency pigtail or is there something else?

Thanks!!!
Bill

 

[Johnny Electron]

Tech support has several cases called in where the Airmar mix and match B175s where having problems on different boats. We haven't confirmed anything yet but I expect a wiring issue as we have had no reports of the Furuno 10 pin B175 units having this problem when connected. Being that the transducer tests well, I don't see how a mix and match would be any different to the sounder than the Furuno 10 pin version unless there is some connection issue where it is not mating up to the correct two pins on the MFD. (TZT3 12 pin has two connections for transducer +/-) I recommend you report the issue with Airmar and see what they say. I will also contact them regarding the calls we have received to tech support. I am sure they will figure it out.

 

[Bill106]

Thank you Johnny! I'm not 100% sure of the connections in Airmar's liw freq pigtail but I will grab it this afternoon and check.

I'm pretty sure the xmit and receive go to CH0 on the TZT if a single, non-duplexed ducer is used, do you know if that's correct? I'm 99% sure that's the way I wired Quitsa's boat

 

[LowTide]

Airmar probably doesn't know anything about the 10p/12p adapter cable, this is a question for Furuno.

The schematic for the 10p/12p adapter cable shows no connections to pins 6 & 7 of the 12 pin (TZT3) side. Pins 6 & 7 are the +/- for CH1 sonar (which runs a B175L). That's why it's not working.

The ridiculously overpriced TZ3-12P-PGT pigtail cable mentioned above does have these wires, but you'd have to cut & splice your transducer cable.

Best bet at this point is probably the ridiculously priced AIR-040-406-10 Y-Cable which can take two 10 pin transducers (like a B175H & B175L) and connect them to the appropriate pins of the TZT3. In your case you could leave the B175H connected as it is now, and connect the B175L to the other unit via the "low side" of the Y cable and leave the high side open (although I'm not sure why you wouldn't connect both transducers to one unit).

 

[Johnny Electron]

Hi Bill each TZT3 (except the 9") comes with the adaptor (000-197-069-10). Here is a direct link to the inner wiring which is posted under the product support page. https://www.furunousa.com/-/media/s...terfacing_and_installation/12_to_10_adapt.pdf. You are correct that any diplexed or single freq transducer should be wired CH0 (Channel 0) onto pins 2&3 of the 12pin (J2) connection. The second channel (CH1) is for when running Dual CHIRP or the DI box. The TZT3 and this adaptor have been out for about three years and working so I don't think the adaptor provided is wrong.

 

[LowTide]

I was under the impression that a high or medium frequency CHIRP transducer (like B175H or B175M), as well as a CW diplexed transducer (like B260) connects to CH0 but a low frequency CHIRP transducer (like B175L) connects to CH1.

I thought this is why you cannot run a B175H & B175M (or B175HW) on one TZT3. One thing is for sure, seems like there is a lot of confusion around connecting transducers to a TZT3.

 

[Bill106]

Thank you Johnny! That's what I thought. I spoke with James and he had your report in hand, apparently there might be some defective or miswired mix n match pigtails out there as he wants it's serial number to see if it's in the suspect batch.

I never really thought it was the 10 to 12 pin adapter (I did swap them but no difference). I'm more suspecting Airmar's low freq only pigtail connects somewhere other than CH0 but will find out tonight when I break out the trusty Fluke.

I know you can connect both to one unit via a Y cable Low Tide, but when doing so with dual B175's you aren't providing the TZT with TDID for either. With a single TZT, that's the way you have to go but with two available, I prefer to connect one to each unit so it's sure to recognize and fully utilize the capabilities.

 

[Johnny Electron]

Hi Bill, To be clear if using the Y cable with two 10 pin single freq CHIRP transducers it is important that the LF side goes to the low and HF go to the HF. If Airmar has a special Y cable that is used to adapt a mix and match; I will defer to them on that. Normally if you are not pairing a set of transducers, the transducer 10 pin goes directly to the adaptor and then to the unit (no Y cable). No Y cable should be involved in a single freq transducer being connected. We only use the Y whenever we need to pair a set of single freq transducers. Because of the wiring, if someone were attempting to use a Y cable they don't need, they must use the HF/MF connection side for any single freq transducer if they plan to not run a pair. So in your example you said that you had a Y cable in place. If using only one single freq transducer, then it must be connected to the HF side of that Y cable so it meets with the proper CH0 connection. Hopefully that makes sense. Ideally; don't use a Y cable unless pairing.

 

[Bill106]

Hi Bill, To be clear if using the Y cable with two 10 pin single freq CHIRP transducers it is important that the LF side goes to the low and HF go to the HF. If Airmar has a special Y cable that is used to adapt a mix and match; I will defer to them on that. Normally if you are not pairing a set of transducers, the transducer 10 pin goes directly to the adaptor and then to the unit (no Y cable). No Y cable should be involved in a single freq transducer being connected. We only use the Y whenever we need to pair a set of single freq transducers. Because of the wiring, if someone were attempting to use a Y cable they don't need, they must use the HF/MF connection side for any single freq transducer if they plan to not run a pair. So in your example you said that you had a Y cable in place. If using only one single freq transducer, then it must be connected to the HF side of that Y cable so it meets with the proper CH0 connection. Hopefully that makes sense. Ideally; don't use a Y cable unless pairing.

My fault for not being clearer in my description Johnny! You explained the constraints much better. I seem to recall seeing a Y cable taking two ducers to one 12 pin port but it did not connect the TDID of either, which would require manual model selection, not always something you can count on being correct.

 

[LowTide]

I was under the impression that a low frequency CHIRP transducer had to be connected to CH1. Based on info here, that appears to be incorrect, sorry for adding to the confusion.

With that said, while it is true you lose TDID with a Y cable, you gain the ability to see both transducers on the same screen at the same time (something you cannot do as far as I understand when they're plugged into different units, please correct me if this is wrong). The only penalty is the transducer selection by model which takes approximately 1 minute, if that. So it comes down to choosing between a 1 minute time penalty vs. the ongoing penalty of no split screen H/L or M/L sonar. Seems like an obvious choice to me.

 

[Johnny Electron]

Lowtide you are correct. It isn't possible to pass two TID wires into one input so when using a set of pairs (hopefully one of the compatible pairs) one must manually select the transducer type. As you say it only takes a few extra seconds and is completely necessary due to mixing two different transducers.

 

[Johnny Electron]

Airmar looked into the mix and match and has found no issues with any wiring. They say that it appears the reports are related to the use of the Y cable for single transducers. Our techs will be on the lookout for any customers using the Y cable with only one transducer. If anyone runs into any mix and match issues please let us know.

 

[LowTide]

Bill, maybe ask your customer if he wants split screen sonar capability...if yes, y-cable it is. Leaves the other machine open for future expansion as well.

I'm curious what the problem is with using the y-cable with one transducer? Is it that you must have a transducer on CH0 when having a transducer on CH1?

 

[Bill106]

James just got me the pinout for the MM plug and while I haven't verified all wires, it appears the blue/black pair are connected to pins 8 and 10 of the 10 pin plug, and hence would be going to CH0.

Since the TDID and temp are working the only thing left to verify are ground and shields. Since I'm getting no return at all, at any settings manual or auto, I'm skeptical it's a shield issue.

I've always preffered to use the TDID function Low Tide. When it first was introduced it was a way for the transducer to communicate with the sounder and some machines were capable of reading the current internal temp of the ducer and would reduce power if approaching an overheat condition. I don't know if they still do but that alone made it worthwhile to me.

 

[LowTide]

You say you got the pinout for the MM plug, but you have two different MM plugs. Did you get the pinout of the LF only MM plug or the regular MM plug? What is different about the LF MM plug? Anyone?

As for the 'overheat' functionality, perhaps someone from Furuno can answer definitively? Does the TZT3 read the internal transducer temperature via the TDID connection, and if so, what does it do with this information?

 

[Bill106]

Yes, just the low freq MM pinout and it meters out through the Furuno 10 to 12 pin adapter exactly as the drawings call for. No high resistance or unwanted connections to other pins, bizarre!

If I hadn't previously direct wired (spliced into the 10-12 pin adapters) a pair of B175H and L's into a pair of TZT16F's I would be questioning the CH0 vs CH1 for the low connection. That installation worked and is still working just fine on Quitsa's boat.