J/30 Class Association Forums J/30 Forum The Boat, Sails and Equipment J/30 Instrument Panel Type A Rebuild

My J/30 hull number 87 has all of the VDO ocean series gauges vs alarm lights.

I finally found a replacement temp gauge but cannot find a sending unit which is 5/8 a very odd size.

Anyone have any ideas where I can buy the remaining instruments? Oil and Tachometer? Is it possible to move to a more modern digital NMEA standard system?

Thanks for sharing...

Dave@j30.us

UPDATED: June 1st @ 8:44 PM CT

BUDGET INFORMATION -> PARTS GAUGES SENSORS MATERIAL COSTS

I have rebuilt the instrument panel on my hull #87 with a goal to get all instruments working. I really like my J/30 hull #87 as this is an older 1979 model with real instruments vs alarm lights. There is minimal documentation about the older type Yanmar panels, so I wanted share information.



CREDIT: Bill Kneller and Sintes Boat Works have been very helpful to coach me on the steps to get everything working. Last but not least, my son Mitchell 3D designed and a friend at work Hans Tharp printed new Bezels.

3D PRINTER FILAMENT TYPES
I wanted to share the various types of 3D filament material. Don't print parts with PLA as this will not last in the heat with UV exposure.

The most commonly used filaments (what most people start with) are:
1. PLA (Polylactic Acid)
✅ Easiest to print
✅ Very common / beginner-friendly
❌ Poor heat resistance (softens ~55–60°C / 130–140°F)
❌ Poor UV resistance (sunlight degrades it)
Good for: prototypes, indoor parts

2. ABS (Acrylonitrile Butadiene Styrene)
✅ Strong, durable
✅ Good heat resistance (~90–100°C)
❌ Poor UV resistance (yellows/degrades in sun)
Good for: functional indoor parts, enclosures

3. PETG (Polyethylene Terephthalate Glycol)
✅ Strong + impact resistant
✅ Better heat resistance (~70–80°C)
✅ Moderate UV resistance
✅ Easier to print than ABS
Good all-around “upgrade” material

4. ASA (Acrylonitrile Styrene Acrylate)
✅ Excellent UV/weather resistance
✅ Good heat resistance (~90–100°C)
✅ Designed for outdoor use
Essentially “outdoor ABS”

SAFETY NOTE:
The best filament to use for the outdoor exposed applications is ASA as the material has good UV resistance. The downside is that ASA cannot be printed indoors unless you have special ventilation and or filtration. The material should be completely dried before printing to produce the best quality. Most people would just print it in their garage. We used ASA filament to print the VDO gauge bezels.

DEVLOP A WIRING STRATEGY
There are two marine wire brands I recommend: (1) SeaChoice 16 AWG and (2) Anchor 16 AWG. To reduce VR (variable reluctor) analog sine wave signal noise, we ran a new wire between flywheel sensor and Tachometer in the new panel using ANCOR Flat Duplex Wire # 179465 Mfg # 120910. The color standards I used for the project are below:
Purple 12 V positive +
Blue 12 V negative - aka Engine Ground. A good ground is your friend to produce quality readings for all gauges.
Orange - magneto signal from VDO 128170-91100 sensor to AXM-120 VR signal conditioner.
Yellow - output signal from VR signal conditioner to ECU Tach input on Dakota Digital SGI-100BT.
Green - output signal from Dakota Digital SGI-100BT to Intellitronix M9001 Digital Tachometer.

YANMAR ENGINES are built in Japan, and Japan uses the British Standard Pipe Thread (BSPT) standard. The danger lies in the fact that the threaded shaft on most of these sensors are 1/8” and the NPT and BSPT versions are very nearly the same. The thread density and coarseness are the same; but the American version cuts the threads at 60⁰ while the British version uses 55⁰. One will screw into the other, but it will leak. There is a third pipe standard, British Standard Parallel Pipe (BSPP). Both NPT and BSPT are tapered, meaning the threaded hole is cone shaped. BSPP threads have parallel sides. I have concluded that even though the 2QM15 was built in Japan, the water and oil sensor threads are indeed NPT.

VDO GAUGES
Across the marine industry, gauge sizes are largely standardized to simplify helm layouts, replacements, and OEM installations. VDO follows these same conventions.
✅ 52 mm gauges (2‑1/16 in)
Oil pressure
Engine temperature
Fuel / water / waste tank level
Voltmeter / battery status
Trim, rudder angle, hour meter
Industry context: This is the most common “small gauge” standard across marine manufacturers [gaugesvdo.com]

✅ 85 mm gauges (3‑3/8 in)
Cutout diameter: ~85 mm
Typical use: Primary engine and navigation instruments such as Tachometer

Supporting this project, I purchased two-hole saws on Amazon 2-1/16 " / 52 mm $16.69 and a 3-3/8" / 85 mm $23.99.

GAUGE LIGHTS: All lights are working fine. ORDERED 600-886 - VDO HID White LED Wedge Type Bulb (Type E) Upgrade. This VDO product 600-866 was purchased on eBay. LED bulbs are much brighter and take a fraction of the energy. See photos below.

VOLTAGE GAUGE: This was easy to get working. The VDO gauge installed was a 2 2/16" universal voltmeter voltage gauge $66.85.

TANK GAUGE: I really like knowing how much diesel is in the tank. Last year, I found the original manufacturer of the aluminum tank (Luther's Repair Shop Inc) and asked them to build me a new tank with a sending until. Over time aluminum develops very tiny pin holes which makes your boat smell like diesel. Mine smells brand new now. The VDO gauge installed was a 301-015 $72.53.

Recommended Tank Replacement Source
Luther's Welding & Fabrications
500 Wood St. Unit 212
Bristol, RI 02809
401-253-5550 p ext 101
Luther's Welding and Fabrication

OIL PRESSURE: Ordered and installed a new VDO 360-006 Oil Pressure dual terminal sending unit This is a standard (not floating) ground model with a thread size: M10 × 1.0 . One terminal will connect to the alarm. The second terminal will connect to the 0-80 PSI gauge. The VDO 360-006 product purchased via eBay arrived on 4/6/2026. Price was $77.34. This product resolved the alarm buzzer issue. The VDO gauge installed is a 350-104 $55.28. NOTE: Used Permatex high temperature thread sealer only at the top layer of threads. The bottom layer of threads serves as the ground contact with engine. Do not use Teflon tape. Again, it is very important to get a good ground with the engine.

ALARM BUZZER: I have a brand-new buzzer, just need to learn how the alarm goes off when key is turned on then stops a few seconds after the engine runs. I would assume this design comes from the oil sending unit there is a negative contact until pressure which disconnects the negative contact. After installing the new VDO 360-006 Oil Pressure sensor, the alarm started working perfectly. When the ignition key is turned on the buzzer sounds. After starting the Yanmar 2QM15, the alarm continued to sound for a few seconds until the oil pressure reached 40 lbs. The buzzer was purchased via Toad Marine Supply. Part number is 104271-91352 and price was $354.04.

WATER: Water gauge is a VDO 310-105 100-250 degrees $82.50. The original OEM part 803/1/11 is a 120-degree water temperature sensor with a 5/8" thread. Normal operating temperature range is 65-77 degrees Celsius. Upper normal temp is 82 degrees C or 180 degrees F. The sensor should alarm when temperature exceeds 95 degrees C 205 F. I ordered a new VDO Water Temperature Sender 5/8 UNF Thread with 95°C Warning Contact | 323-803-001-011D | $167.39 from VDO Workshop Warehouse in the Netherlands (Merlin's Motorsport in UK is an alternate source). The correct sensor was installed over the weekend. Water temperature gauge is now working as of 4/26/26.

TACHOMETER: The legacy tachometer is no longer available in the market. The specifications for the OEM tachometer can be found -> here. After replacing the Yanmar 128170-91160 sensor is a flywheel (97 teeth), I measured the output voltage and resistance to confirm within expected specification ranges from the point of sending unit and instrument panel.


DIGITAL TACHOMETER
If you want a modern tachometer, try the design below. It is recommended to clean the sensor VR signal from sensor and install a calibration product. The Dakota Digital allowed me to fine tune calibrate the tachometer. There is a Bluetooth interface for easy programming.
Yanmar 128170-91160 sensor -> AXM-120 VR Conditioner -> Dakota Digital SGI-100BT Calibrator - > Intellitronix model M9001 Digital Gauge

VR Conditioner
To clean the magento sine wave signal, I purchased an AXM-120 VR Conditioner which converted the VR (variable reluctor) analog sine wave signal produced by the Yanmar 128170-91160 sensor to a 0–5V square wave signal. I connected the cleaned signal to a Dakota Digital SGI-100BT tachometer input. The digital gauge is a 3 3/8" Intellitronix model M9001 cost was $117.09. When sending a test signal from Dakota to Digital Tachometer, this works perfectly.

Photo of the AXM-120 Variable Reluctance (VR) Signal Conditioner with wiring harness.


PANEL MATERIAL:
Photo of the first panel design is below. The first panel was made using Polycarbonate clear plastic 24" x 24" 3/16 inch thick cut to 7.5 " x 12.5" with RockRose 7D Super Glossy Black carbon fiber vinyl wrap both materials purchased via Amazon. The vinyl wrap was showing air bubbles after heat.



Photo of the final panel design with real carbon fiber. I changed the design! Ordered a solid piece of Carbon fiber EconomyPlate™ Solid Carbon Fiber Sheet ~ 3/16" x 12" x 24" Finish: Gloss/Texture SKU: FEPL06G*90*1224. This sheet replaced the Polycarbonate plastic with vinyl covering. The new design was implemented on May3rd, 2026. It looks amazing!


Photo at night BEFORE LED bulb retrofit.



Photo after LED bulb retrofit.



Instrument Panel Upgrade Guide (in progress)
Instrument Panel Upgrade Guide - 2QM15 1979

If your hull number is above 87 and you have instruments vs alarm lights, please reply. I want to determine what the last hull number with the instruments before moving to alarm lights. Also post your engine model. I have a theory that the 2QM15 engines came with instruments with the 2GM15 engines with alarm lights.