Silverleaf VMSpc Install and Use
David E. Damouth www.damouth.org
20 May 2008
After thinking about it for a couple of years, I finally got serious about installing a Silverleaf VMSpc.
Silverleaf makes a broad line of monitors which display a great deal of information about engine and transmission performance. See www.silverleafelectronics.com/. Their VMSpc product is unique in that it provides all the functionality of their hardware displays, but uses software on a laptop computer to display all the information on the laptop. The layout of the VMSpc information on the laptop screen is highly customizable, and can coexist with other laptop software. For example, here's a photo of my initial attempt to show the subset of VMS information I want, along with my Street Atlas mapping and GPS navigation display:
Screen
Shot with VMSspc and Street Atlas
(Click the photo or the above
link for a larger image.)
The first problem in ordering and installing a VMSpc is to identify the data connector in the motorhome, and verify which of two common connector types it uses. This isn't trivial. By sliding the driver's seat all the way back, I was able to create enough space for me to lay on the floor with my head under the dashboard far enough to see what was there. But I saw only a maze of thick black wiring harnesses, and no connector that looked likely. Eventually, I had to remove the foot rest which is screwed to the floor, and to cut many of the cable ties that held folded up bundles of excess harness length in place, and was then able to move successive layers of cable out of the way so as to peer behind them. I finally found the connector. It's grey, mounted on a black metal bracket which is attached to the firewall to the left of the steering column. It has a grey cap covering the connector, which twists counterclockwise about a 1/4 turn to remove, retained with a lanyard made of cable ties. Interestingly, the cap has an o-ring inside to make a weatherproof seal. "Deutch" is printed on the cap. On the same bracket adjacent to the connector is a momentary-contact rocker switch labeled "engine check". There is an identical connector in the engine compartment, mounted in the bulkhead above the radiator, to the left of the expansion tank, and partially hidden by the overflow tube from the expansion tank. My connector has six pin positions - five in a circle with one in the middle, of which only 4 actually have contact pins. Some RV's have similar 9-pin Deutch connector.
Armed with this information, I searched for Internet vendors for the VMSpc, I found MonsterMarketplace.com . Their price is $340. But they were out-of-stock. I also checked rvupgradestore.com. They listed the same price and were also out of stock.
So I called Silverleaf, who confirmed that they were awaiting a new production run, which wouldn't be available for a month or so. After I complained a bit, they said that they had a few factory-refurbished units, with the same warranty as a new one, for $276, and that they were saving them for people with an urgent need. I was anxious to get this installed before our upcoming spring trip, and convinced them that I qualified with an urgent need. The unit arrived in just a few days.
The product consists of a small black box called a JIB, containing the interface electronics, a special cable which connects the JIB to the motorhome data connector, and a cable connecting the JIB to an RS-232 serial port on a pc. Of course my new PC doesn't have a serial port, so I quickly jumped on the Internet and ordered a serial-to-USB adapter. While waiting for it to arrive, I borrowed an adapter from another application. I had already downloaded and installed the (free) software on my new laptop - a Dell Lattitude D830.
The installation was uneventful: find a convenient place to mount the JIB under the dash; plug in the cables; then find and connect a 12v. power source for the JIB. I chose to use a power source that is switched on and off with the ignition - the same one I use for my laptop and GPS.
The next task was to configure the user interface. The software has a preconfigured "example" interface which is a good starting point. Selecting, moving, and sizing the many gauges is a simple drag-and-drop task - but only experience on the road will determine whether I did it right.
I've now used the VMSpc for several trips. With all those new numbers to look at, it's hard to keep my eyes on the road. But watching the numbers certainly makes the trip less boring. Here are just a few initial observations:
- The transmission indicator is a big help. My motorhome has Allison's simple transmission panel which shows only the gear selected, not the actual gear currently in use. VMSpc shows both, as two big numbers in the upper left-hand corner of the display - which show question marks when the engine is not running.
- The "tank minder" gauge is frustrating. It has to be manually reset whenever the fuel tank is filled, and I can't seem to remember to do it. The equivalent function in my VW Passat resets itself automatically at each fillup. The "tank miles per gallon" reading in the tank minder has never worked right. In its properties, there is a check box for "calculate using Recent MPG". Regardless of whether this box is checked, the reading is often nonsense.
- The speedometer is surprisingly accurate - agreeing closely with the speed shown on the GPS.
- I don't know yet whether watching the fuel economy data will have a significant effect on overall fuel economy.
- I set some audible alarms on critical things that I might not otherwise notice in time. In particular, engine oil pressure. But I started getting nuisance alarms. When quickly slowing to an idle after traveling at highway speeds, the oil pressure drops remarkably low - less than 25 psi. This is with freshly changed 15W-40 non-synthetic oil. I've now reduced the alarm trigger level several times. It is currently set at 20 psi - low enough so that I worry.
- Engine oil temperature apparently isn't measured in the Cummins ISB - it always shows zero. I'll remove this display element
- The Engine coolant thermostat seems to be set at 190 degrees. I've seen the coolant temperature as high as 193 under heavy continuous load, and have now set the alarm at 200 degrees.