Volvo SX-A trim sensor problem.

[Davy8or]

I have a 2010 Volvo Penta SX-A 1.60 I/O drive and the trim indicator on the dash panel isn't working anymore. When I turn the ignition on, the needle on the gauge goes from the resting place on the pin to the full up indication. It doesn't matter where the drive actually is, it will always read full up. I have tried removing the sender from the drive and rolling it's shaft back and forth, but it makes no difference.

I have looked it up and the part number for this sensor is 22005045. It is a three wire "non-contact" type sensor. It seems to cost about $230 so I really want to know where the problem is before just buying this part. Removing this part completely from the boat will require cutting the wires as the stupid boat builder provided no access to the inside of the transom area. You basically have to remove the engine to get back there, so cutting and splicing wires seems easier.

My question is- are there diagnostic procedures I can run to be sure the sensor is the problem, or if the gauge is the problem, or the wiring is the problem. Visual inspection of all three as best I can, shows them to be in excellent condition on the outside.

I will also mention another problem I am having with this boat only because I suppose there is a remote chance the two problems might be related as they are both electrical in nature. This boat has always since the day it was new, blown the fuse for the NAV / Anchor lighting while underway. When you test the system on the trailer, it works perfectly and the load on the fuse is well below fuse capacity when metered. Take it out on the water and the fuse blows. I assume there is bad wiring I need to track down somehow that when it gets giggled, it shorts out. I only mention this other problem as I wonder if this shorting may have effected the trim sensor too?

Any help is greatly appreciated! Thanks in advance,

Dave

 

[Augoose]

I think that's the position the gauge will go to when it senses an "open" circuit, or infinite resistance. Try disconnecting the leads from the sending unit at the back of the gauge and checking resistance between the leads to verify whether the sensor itself is operational. The gauge is essentially a potentiometer, so as you turn the sending unit shaft, resistance should go up and down. You can also test for 12v at the back of the gauge when ignition is on (likely purple lead) however I think the fact that the gauge pegs at full up means you have 12v there. Most likely a broken lead between the sending unit and the gauge.
Mine failed at two locations - at the sending unit itself and then again at a connector behind the back of the engine.
Y

 

[Davy8or]

I think that's the position the gauge will go to when it senses an "open" circuit, or infinite resistance. Try disconnecting the leads from the sending unit at the back of the gauge and checking resistance between the leads to verify whether the sensor itself is operational. The gauge is essentially a potentiometer, so as you turn the sending unit shaft, resistance should go up and down. You can also test for 12v at the back of the gauge when ignition is on (likely purple lead) however I think the fact that the gauge pegs at full up means you have 12v there. Most likely a broken lead between the sending unit and the gauge.
Mine failed at two locations - at the sending unit itself and then again at a connector behind the back of the engine.
Y

Thanks for the suggestion, today I'll see what I can find with this info. Was your sensor the three wire type too? If it's just a simple potentiometer, I'm wondering what the third wire is for? It would be so wonderful if I could have a complete wiring diagram for my boat like you can get for your car, but alas, I can't seem to get that.

 

[muc]

All potentiometers have 3 wires.
Volvo sometimes uses all 3, sometimes just 2. It depends on what computer is on the engine. They designed this sender so it could be used on all of their current product.
While the trim sender is the common part that fails. There are other things that can cause this symptom.
I’ve had a couple of Volvo powered boats with this same symptom and it was the tachometer that was bad.
Troubleshooting this requires that we know exactly what engine and gauge package you have.
There was one year that letting the trim sender wire touch ground would kill the engine. But they fixed that the next year.

 

[Davy8or]

All potentiometers have 3 wires.
Volvo sometimes uses all 3, sometimes just 2. It depends on what computer is on the engine. They designed this sender so it could be used on all of their current product.
While the trim sender is the common part that fails. There are other things that can cause this symptom.
I’ve had a couple of Volvo powered boats with this same symptom and it was the tachometer that was bad.
Troubleshooting this requires that we know exactly what engine and gauge package you have.
There was one year that letting the trim sender wire touch ground would kill the engine. But they fixed that the next year.

The engine is the 5.0 GXiC-J. I have no idea about the gauge package, so I'm attaching these pictures-

 

[stouchton]

Just some info on the trim sender.....

Volvo Penta trim senders measuring approximately 11 ohms when in the full down position. If you would disconnect your trim sender back at the junction just inside the transom mount, you can attach a 11 ohm resistor (or 10 ohm which is a more common value) - your gauge should then read "almost down". I have never seen one with a good sensor that reads all the way down.

On my boat I changed both of my sensors. I was unable to pull new cable thru the transom mount since I cannot get back there (I called the boat manufacturer about access, and they informed me all that went together before the deck went on.....).

I cut my wires right at the old sensor, and spliced in a new sensor using water proof heat shrink splices. Mine was 2 wire install, so I cut the third wire. While I had the wires cut I tested the rest of the system to make sure all was OK by temporarily hooking everything up.

After reading many reviews on replacement trim senders, I did not install Volvo Penta and went with a lesser cost option. this lesser cost option did not read 11 ohms all the way down, it read 17. So my "almost full down" is not quite as far down.

In the near future I will probably install a hydraulically driven indicator that does not get exposed to the elements.

 

[Thalasso]

part # 21484383 is the sensor for a SX-A
http://www.volvopentastore.com/Gimba...view_id.775538


Just installed one on mine this year

https://leadersrpmshop.com/volvo-pen...a-dps-a-dps-b/
$184.94

 

[muc]

The engine is the 5.0 GXiC-J. I have no idea about the gauge package, so I'm attaching these pictures-

When you turn the key on. Do the needles on the gauges move around stopping at 1/2 and full scale before settling in where they should? This could help us determine if they are analog or digital. I can't tell from the pictures.

The engine serial number might help me know if you have a 3 wire or 2 wire sender. That engine could use both.and the troubleshooting is different.

Both the sender part numbers that you and Thalasso posted are good numbers. The only way to be sure is to use the serial or product number for the transom plate (TSK)

stouchton is correct about the ohm readings, but I wouldn't use his cut and splice method. Your trim system runs through the engine computer.

Volvo recommends using a scan tool to troubleshoot this system. There are multiple trouble codes listed in service manual #7749393 -------- but only if you have analog gauges, if they are digital then the gauge manufacturer provides the troubleshooting.

Welcome to the world of Electronics. What used to be a simple ground the sensor and see what the gauge does and now doing something like that can kill the engine.


And no the nav/anchor light isn't run through the engine computer yet.

 

[Thalasso]

Here is a repair manual for your drive. Save it somewhere for future use


https://us.v-cdn.net/5020499/uploads...c810973749.pdf

 

[Davy8or]

When you turn the key on. Do the needles on the gauges move around stopping at 1/2 and full scale before settling in where they should? This could help us determine if they are analog or digital. I can't tell from the pictures.

The engine serial number might help me know if you have a 3 wire or 2 wire sender. That engine could use both.and the troubleshooting is different.

Both the sender part numbers that you and Thalasso posted are good numbers. The only way to be sure is to use the serial or product number for the transom plate (TSK)

stouchton is correct about the ohm readings, but I wouldn't use his cut and splice method. Your trim system runs through the engine computer.

Volvo recommends using a scan tool to troubleshoot this system. There are multiple trouble codes listed in service manual #7749393 -------- but only if you have analog gauges, if they are digital then the gauge manufacturer provides the troubleshooting.

Welcome to the world of Electronics. What used to be a simple ground the sensor and see what the gauge does and now doing something like that can kill the engine.


And no the nav/anchor light isn't run through the engine computer yet.

Thank you so much for all the help! When I turn the key on, the needles just snap into position. This makes me feel they are analog. In the case of the trim gauge, when the key is off the needle rests on the pin like in my above photo and when you turn the key on, it immediately snaps to the full up indication.

I have attached what I think to be useful info about the engine and transom plate. Is the scan tool the same OBDII type you use on cars? Unfortunately I am in the the same boat as stouchton. My options to replace the sensor seem to be, cut and splice like he did, or cut access holes in the top deck (like the damn factory should have done), or remove the engine. Splicing seems easiest, but given the connection to the engine ECU, I get your point. A failure of the splice insulation could lead to a dead engine on the water.

Never again will I buy a boat you can't really work on.

 

[Davy8or]

Here is a repair manual for your drive. Save it somewhere for future use


https://us.v-cdn.net/5020499/uploads...c810973749.pdf

Thanks so much! I have downloaded and saved it. Unfortunately, it doesn't seem to mention anything about the trim sensor, but it will be handy in the future I'm sure! Much better than my generic Seloc manual.

 

[jtm3]

This forum constantly amazes me. Just bought a replacement trim sensor for my 2001 VP SM 1.78 DP and when I was talking to a local VP mechanic he told the story about how there was that period when the grounding would knock out the engine....of course he didn't explain it as well as was discussed above.

Anyway, I have only had the boat for one season and am slowly working my way through my "things to fix" list. I have my drive off to change the bellows and have decided to install a new sensor (got it through Amazon Prime for $135). Anyway, the reason I posted is there is a pretty good you tube video on swapping it out with the drive on. https://www.youtube.com/watch?v=q47pa3uvvfo

With the drive off, you have pretty good access to the rubber grommet so that is why I decided to do it. I was on the fence, because I can pretty much get a sense of the trim based on how the boat is running. Hopefully, swap it out tomorrow, along with the bellows and put it back together and in the water this weekend.

Thanks, love the info I learn from this forum.

 

[BRICH1260]

I`ve replaced two sensors. One I spliced with the drive on and the other I was able to feed the wires, in tact, through the transom with the drive off. The splice job never worked that great, very intermittent readings. I would recommend that if you have the time, to remove the drive first. Yes, it takes a little longer, but it is better keeping the electrical lines in tact, in my opinion as splices and water don't mix well.

The best thing is to get used to not using one and go by timing. Count the seconds up and down an remember, as any new one will fail sooner or later. Probably sooner than later.

 

[Davy8or]

I`ve replaced two sensors. One I spliced with the drive on and the other I was able to feed the wires, in tact, through the transom with the drive off. The splice job never worked that great, very intermittent readings. I would recommend that if you have the time, to remove the drive first. Yes, it takes a little longer, but it is better keeping the electrical lines in tact, in my opinion as splices and water don't mix well.

The best thing is to get used to not using one and go by timing. Count the seconds up and down an remember, as any new one will fail sooner or later. Probably sooner than later.

That's what I did all last season. I went without. I live in a boating community where the boat spends it whole life on a boat lift. Right no I have it out on the trailer, so I figure it's a good time to fix this issue. We bought this boat brand new and so I kind of want to keep it as much like that as possible. 100% working. If that becomes too much of an impossible thing to achieve, I'll do as you say and go back to what I have done for the last year, trim by feel and Speedo.

 

[muc]

Never again will I buy a boat you can't really work on.

I understand your unhappiness.But after working 25 years for dealers out of my 35 years in the boat business. I have found that bells, whistles and how much passenger room is what sells most new boats.

Thanks for posting your serial numbers.
The correct sender part number is 21484383 for your TSK
Your engine does use all 3 wires
Your engine does have the resistor installed in the harness so if a trim wire does short to ground the engine will NOT kill.
Yes it sound like you have analog gauges. It's about 90% that the sender is whats bad.
There are tricks that techs use to speed up this job. Most times I've done this job, it takes longer to move all the wake boards, tubes, life jackets and assorted crap people leave in their boat than it does to swap a trim sender. Maybe ask your dealer for a $$$ on replacement. Don't cut and splice a $200+ part, it won't last.

The video posted above has almost nothing in it that's right for your boat.

 

[muc]

Is the scan tool the same OBDII type you use on cars?

No, your best bet is Rinda Diacom or Techmate

 

[Davy8or]

I understand your unhappiness.But after working 25 years for dealers out of my 35 years in the boat business. I have found that bells, whistles and how much passenger room is what sells most new boats.

Thanks for posting your serial numbers.
The correct sender part number is 21484383 for your TSK
Your engine does use all 3 wires
Your engine does have the resistor installed in the harness so if a trim wire does short to ground the engine will NOT kill.
Yes it sound like you have analog gauges. It's about 90% that the sender is whats bad.
There are tricks that techs use to speed up this job. Most times I've done this job, it takes longer to move all the wake boards, tubes, life jackets and assorted crap people leave in their boat than it does to swap a trim sender. Maybe ask your dealer for a $$$ on replacement. Don't cut and splice a $200+ part, it won't last.

The video posted above has almost nothing in it that's right for your boat.

Thanks again for your help! All good information. I won't be taking this to a dealer because there are no dealers for this boat anywhere near 100 miles or more for this brand. In addition, the boat repair places locally I have interfaced with I have NOT been impressed with.

I have been wrenching and fabricating most of my life. That's a little over 40 years on motorcycles and cars. I spent about 10 years on commercial diesel trucks and I have done all the work on our families Jet Skis for 20 years now (although they are mostly like motorcycles). For the last 7 years I've also done all the work on my airplane. That was a new learning experience, but now it's just how it is.

Having said all this, this the first and only "real" boat I have worked on. It's yet another new discipline to learn. Two years ago I did the big maintenance service on this boat that required pulling the outdrive, so I built my own slick adjustable outdrive stand to do it. It's just how I am. However that's when I discovered how hard it is to get quality service manuals for power boats. I used a SELOC manual for that job and it was OK I guess.

I say all this because I'd like to know if there is any way I can get proper service manuals for my boat, so that I can diagnose and fix stupid little problems like this. Is there a test procedure for the trim sensor before I just go and buy another one and hope for the best?

Cars- I can get factory manuals that cover bumper to bumper. Motorcycles- I can get manuals that cover tire to tire. PWCs- I can get manuals that cover bow to stern. Diesel trucks- I can get bumper to bumper on the chassis/body/drive and engine from the engine company. Airplane- The airframe company gives me one manual, the engine company gives me a second manual and the propellor company gives me a third manual.

Boat- nobody wants to easily get me anything. What a PITA!

Anyhow, whatever you could provide me on either how to get a proper workshop manual for Volvo Penta, or the diagnostic procedure for the dumb trim sensor would be awesome! I'll figure out how to repair the problem once I'm sure what it is, no problem.

Thanks again.

 

[Davy8or]

No, your best bet is Rinda Diacom or Techmate

Great. More stuff to buy.

 

[skydiveD30571]

I can't promise it's 100% accurate, but here's a link to a shop manual for the 5.0GXi engines (A-F) so it is at least probably similar enough to give you good info.

http://boatinfo.no/lib/volvo/manuals/5057a-f.html#/0

The shop manual for SX-A drive that you saw in the thread above is also on this website. It's difficult to impossible to access on a mobile device however.

 

[BRICH1260]

I`ve been able to find most of my engine and drive manuals on ebay. Some were printed and some were electronic. You might do a search there. Don't get discouraged, there is a sense of satisfaction you will get once you are comfortable with the boat engine and drive. It sounds like from your mechanical pedigree that you will have it down in no time.