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: May 18th @ 5:00 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 panels, so I will share as I learn and improve.

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 printed new Bezels. You will see a prototype on the lower left water temp gauge in the new panel photo (scroll down). I will install the others soon.

NOTE: Yanmar engines are built in Japan, and Japan uses the British Standard Pipe Thread (BSPT) standard. 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.

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.

What is currently working:

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.

What is not currently working:

TACHOMETER: I am going with a digital tachometer (see upgrade guide below). My sensor is a flywheel (97 teeth) magnetic type, so I am looking for a product to convert the magnetic signal to a squared wave with 6-9 volts to match the W type signal you would get from the alternator tachometer design. Another possible option, does my current alternator have a W terminal output? Ordered a Dakota Digital SGI-100BT to convert the magneto sensor signal to squared wave which is what the digital tachometer needs. The digital gauge is a 3 3/8" Intellitronix model M9001 cost was $117.09. Installed the Dakota Digital converter over the weekend which confirmed I was not getting any signal from the sensor. Sensor 128170-91100 has been replaced. Next steps - program the Dakota Digital SGI-100BT in flywheel mode with 97 teeth, low voltage mode with pull-off voltage disabled. The specifications for the OEM tachometer can be found -> here. I measured the output voltage and resistance to confirm within expected specification ranges from the point of sending unit and instrument panel. Everything checked out within specification ranges. When sending a test signal from Dakota to Digital Tachometer, this works perfectly. May 17th Update: ran a new shielded twisted pair 18-gauge wire between the sending unit and Dakota Digital and confirmed 4.5 volts on the input side of SG-100BT. Still no luck. Ordered an AXM-120 Variable Reluctance (VR) Signal Conditioner to clean up the signal to SGI-100BT.



Of course, I will post additional information as I progress.

Photo of new panel is below. New panel was initially 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. NOTE: 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