Trim Gauge Input

[dcrahn]

As part of my boat restoration I am installing all new gauges. I sure most typically use the most common brands in the marine industry, but for me being the drag racer that I am, I am partial to Autometer. There quality is second to none and I'm sure that carries over to their marine line of products. I'll be using their Ultralite Pro Comp Marines series and they have a trim gauge in that series. It works with 0 Ohm Down/90 Ohm Up trim level sending unit. Does anyone know what the output is that Volvo Penta used for their sending unit?

[Viper]

It would help if you could provide the transom assembly numbers, then I'd be able to find the part and probably the spec. Having said that, you could measure the unit on your current assembly and go from there. If it's out of range for what you need, a simply Ohm's law calculation and resistor or two can get you in the right range.

[dcrahn]

Source of the post It would help if you could provide the transom assembly numbers, then I'd be able to find the part and probably the spec. Having said that, you could measure the unit on your current assembly and go from there. If it's out of range for what you need, a simply Ohm's law calculation and resistor or two can get you in the right range.

Are you referring to the VIN of the boat or the number of the outdrive?

[Viper]

Volvo will usually supply three labels; one for the engine info, one for the drive, and one for the transom assembly. Each system will be marked individually but if it was done right, there should also be all three indicated on the engine for easy access indicating the original package that was installed in the boat, either on a rocker cover or flame arrestor cover depending on the vintage/model. Usually black and silver labels.

[dcrahn]

Source of the post Volvo will usually supply three labels; one for the engine info, one for the drive, and one for the transom assembly. Each system will be marked individually but if it was done right, there should also be all three indicated on the engine for easy access indicating the original package that was installed in the boat, either on a rocker cover or flame arrestor cover depending on the vintage/model. Usually black and silver labels.

The original engine is still in the boat, so whenever the rain lets up I'll go out and check. I know there is a label on the valve cover from a photo I have, but it's unreadable.

[Viper]

I assume your boat is in the water. If you don't see a transom assembly number on the engine, look for a label on the inside transom plate. If it's out of the water, look on the outer transom assembly. A picture of the drive and or transom assembly would also help identify what you have.

[dcrahn]

Source of the post I assume your boat is in the water. If you don't see a transom assembly number on the engine, look for a label on the inside transom plate. If it's out of the water, look on the outer transom assembly. A picture of the drive and or transom assembly would also help identify what you have.

It's on a trailer but pouring down outside right now. I do know the outdrive is the AQ290-SP.

[dcrahn]

LOL, I still haven't had the chance to check the labels out. The rain I was getting has changed to SNOW . This is something that only happens in my area (19 miles NW of Savannah, GA) about once every decade.

[Viper]

I think I know the unit you have anyway. The only spec I can find is from a low reading less than 100 ohms to 800-1100 ohms.

The fixed resistance measured between red/white and black/white wires (early style - measure between green/white and black/white wires) should be about 800-1100 ohms. It's not necessarily a bad unit if it falls outside this range.

Measuring the variable resistance is taken between the green/white and the black/white wires (early style - measure between red/white and black/white wires). Turn the shaft slowly and the value should increase from low to high without sudden jumps and eventually end up at the high number noted when the fixed resistance above was taken.

I'd confirm the resistance you have first then go from there. Do you have the round analog gauge or the square digital option? If you have the analog gauge, check the back and see if the is a dip switch and a rotary pot there.

[dcrahn]

It's the round gauge that has the colored range sweep from green/yellow/red.