I set up a tire pressure monitoring system this evening in preparation for our trip to Half Moon Bay, CA for some R&R the weekend before the big Pumpkin Festival. This one is Truck System Technologies TM-510RV.
There is a picture of the box and a link to the manufacturer's YouTube video at the bottom of this post, as well as some pricing info and sources.
The system I choose comes with six wheel sensors that measure pressure and temperature and communicate via RF to the monitor/receiver unit located in the cab. This particular manufacturer has models with wheel sensors in two flavors: valve stem buttons the size of small mushrooms that are fairly light
and install with a special wrench, and the larger flow-through sensors that have user replaceable batteries and don't need to be removed for inflation. These are rather more expensive, maybe 2x and the two systems, despite being from the same manufacturer, don't interchange with one another.
Since I have an older truck without any tire monitors if its own, I chose the six sensor system, and I went with the less expensive caps. Installation takes about an hour. Installing the monitor caps is fairly quick; just remove the tire valve covers and screw on the button sensor using the special wrench. Of course it's a good idea to top off all your tires
to a known cold operating pressure first. There's half an hour.
Once installed, the sensors begin transmitting, but to be discovered by the display monitor, you need to key in the four digit code stamped on each sensor, which is unique to the sensor. You can imagine using just four buttons, + - Mode and Set keys, it takes a little while to enter "AC3F" or whatever you might have, plus you need to tell the monitor which tire is which on a little pictorial. The system supports up to 22 tires! Whether you have a single axle
trailer, a dually tow truck, or an eighteen wheeler pulling a Suzuki Samurai, you should be covered if you invest in additional sensors.
The monitor includes a short antenna and a larger dipole antenna if you have a really long rig. My monitor had no trouble picking up the farthest tire without the need for the larger antenna.
After the sensors are programmed you can set the monitor alarm pressures (lo and high) and max temperature. The system will readout in degrees C or F. Tire temperature monitoring does work much better with metal valve stems that will conduct temperature to the sensors more readily.
The recommendation is to set the monitoring pressure alarms at 20% over normal and 10% under and leave the tire temp alarm about 157F
After configuring everything, the system will shift to a polling display that cycles through the assigned sensors and shows temperature and pressure of each tire for five or ten seconds as well as its physical position with a flashing tire in an overhead schematic. Of course you can manually override this and check individual tires
at will. If the temperature or pressure goes out of the set range, an audible alert activates that needs to be cleared with a button press.
In setting up my system I found that two of the six sensors would not communicate. I checked the codes and reinstalled, but even using the dipole antenna and moving them to the nearby front wheels of the cab, they still didn't show. I emailed the support line and expect they will send some replacements. For the time being I am leaving the front wheels of the truck unmonitored. I figure I will get some feedback through the steering column if things start to go awry.
Some additional details about the system:
The display has an on-board battery
that will run for 30 hours On a charge. And it has a backlight and motion sensor that will shut down when you stop moving.
life is supposed to be around 5 years on the sensors, but the system I bought has a 2-year warranty. It comes with the monitor/display, a 12V cigar lighter adapter, a second 12V connector and cable for hard wiring power if you choose, six tire sensors, two of the special wrenches, some mounting clamps and Velcro pads for the display and the instructions.
My comments so far are that the wheel sensors are probably too large for car tires
unless you get the wheels balanced with them installed. I think they're fine on SUV or Truck tires, and of course the trailer doesn't care much.
I'll update you when we return from our trip. It's great peace of mind knowing that I'll get some early warning if the trailer tires start to go flat or heat up, due to delamination of the plies or something. Generally you wouldn't know until the blowout.
Price is something like $250 retail via Cabella's or $300 at Camping World. I believe I paid around $150 from an EBay seller, but That could have been a one-time deal.
I'll post up some pictures if my phone will let me!