Volvo AQ Trim Module

[boatrup]

Hello everyone
For those of you with AQ drives, I could use a bit of help. The trim sensor module part # 857534 on my boat is bad. The trim limit, and trailer (max lift) limit relays still work, but the gauge does not. I have already replaced the sensor. I have tested the gauge and know it is good. So it is that middle man module that is bad. I know I can buy a used one, but really don't want to do that, as it'll be likely to fail as well.

So, I am going to build a replacement module. Unfortunately, without a working reference I need someone who has a working one to take an ohm meter and measure the input to the module and output from the module. With that I will be able to design and make a replacement module. The original module is potted with an epoxy, so I cannot simply disassemble and duplicate it. For the heck of it, I did email Volvo Penta to see if they would give me the schematics so I could build an exact replica, but I doubt they will provide that.

Is anyone willing to take those measurements for me?

 

[Scott Danforth]

With drive down measure sensor resistance. With drive up, measure sensor resistance

 

[boatrup]

With drive down measure sensor resistance. With drive up, measure sensor resistance

Does that module really just output the same as its input?
I knew I could measure the sensor resistance myself. I just thought the module output something different and I needed to know the correlation between the input and output.

 

[Scott Danforth]

No, the module just triggers the relay at 7 degrees up and converts the output to a simple ratio for a gauge

If you look, you can even find NOS modules and gauges.

I did for my Square AQ290DP trim gauge

 

[Donald0039]

How much is a new one? You not only need to design it, you need to build it for the marine environment.

A couple of years ago I looked for a module to control an electric fuel pump when converting from a manual fuel pump. I could not find one for the marine environment and went back to mechanical fuel pump.

 

[boatrup]

How much is a new one? You not only need to design it, you need to build it for the marine environment.

A couple of years ago I looked for a module to control an electric fuel pump when converting from a manual fuel pump. I could not find one for the marine environment and went back to mechanical fuel pump.

The problem is, there is no new one anymore. If there was I would absolutely buy it. Though, if I do make a new one, I will gladly make them available for anyone who wants one.
Marine environment is pretty easy for these things, I'll do exactly what volvo did. I will just pour epoxy all around it and make it a solid epoxy block, after first conformal coating the PCB. Thats all volvo did with the original module, and why I cannot take it apart to fix it.
Fortunately electronic design is something I have a lot of experience with.

 

[Scott Danforth]

if you bypass the block and just run a gauge, just know that at 8 degrees, you stop