FAQs

Scanner, Checkmate, RVCHECK, Express Mobile, Express Garage - so many models to pick from. Which one is right for me?

The Scanner, Checkmate 1200 and 1200-A are Trailer Lighting System testers only. The Express Garage, Express Mobile and RVCHECK test not only Trailer Lighting Systems, but Trailer Brake Systems as well.

If you need to test trailer air brake systems your decision is easy. The Express Garage tests trailer Air Brake Systems as well as Electrical Systems in your shop. For your service truck, there is the Express Mobile Air and Electrical Tester. Both of these units feature Radio Remote-Controlled air brake operation in addition to complete built-in Scanner Trailer Light Testing equipment.

If you just want to test trailer electrical systems, either a Scanner, Checkmate, or an RVCHECK might be just what you’re looking for. Any of these are equally at home in your shop or your service truck.

As a rule of thumb, SWI recommends the Scanner for shops testing multiple trailers a day, because its Auto-Scan feature really does save lots of time. Click here to see the payback time. The Checkmate is a more basic tester. It’s geared more toward shops testing small trailer volumes, and the new RVCHECK or the Checkmate 1200-A are recommended for RV and utility trailers with electric brakes.

How long is the trailer cable?

The Scanner and Checkmate 1200 and Checkmate 1200-A come with an 8 foot light cord. The RVCHECK has no cord. Instead, a seven-blade round RV-type socket is mounted on the carrier, because the cord is usually part of the trailer. The air hoses and light cord of the Express Garage pull up out of the cabinet, and can comfortably reach connections that are 7 feet 3 inches above floor level.

The Express Mobile has an SAE 7-Pole Socket instead of a light cord and plug. The light cord and plugs, as well as the air hoses and Gladhand connectors are not provided because length and style of these will vary with each installation. We can provide custom light cord and air hose assemblies as extra-cost options –Contact us for pricing.

What if my trailers don't use the SAE 7-pole plug?

Regardless if you’re working with the SAE protocol, or the RV standard, adapters are available to get you to another plug configuration. For example, you can go from one RV plug type to another or cross over to the SAE type if you need to. The adapters are described in our product store section.

Can these units be used to test trailer ABS?

Yes. Modern ABS computers test themselves when the trailer’s auxiliary circuit is first powered or, on some systems, each time the stoplight circuit is powered. The Checkmate, Scanner, Express Garage, and the Express Mobile can power a trailer’s circuits to initiate the self-test. The Express Garage and Express Mobile have a handy ABS test switch so you can control the auxiliary and stoplight circuits with the remote. This allows you to initiate the ABS self-test from behind the trailer. Read more in Testing ABS.

What about electric brakes?

For testing electric brakes, we strongly recommend the new RVCHECK. The RVCHECK has an ammeter dedicated to measuring electric brake coil current draw. By checking current being drawn by the brake coils, you’ll be able to tell if all of the brake coils are operating.

The Checkmate 1200-A is also equipped with an ammeter, but it’s designed for SAE lighting systems. If you’re shop does mostly SAE testing, but occasionally sees an RV or two, the “dash A” might be a good choice. See Making Other Tests.

Can I use these units to feed into a tractor's light cord in order to check the tractor's lights?

We don’t recommended this. It’s best that you never use any light tester to feed into a tractor’s light cord! With today’s fabulously complex electrical systems, back-fed current from the tester could conceivably cause damage to the tractor’s electronics. In any event, the relays and switches that control tractor lighting functions stand in the way of making a complete test. Finally, there are still some tractors around with positive ground systems. Plugging a negative-ground light tester into a positive-ground tractor would result in possible damage to the test equipment and the tractor.

Can I use one of these units to test the output of the tractor's light cord?

You could use your Scanner or your Express Garage, but that’s a pretty clumsy way to make that test! A much better way (and a safer way) to test tractor plug outputs is to use an inexpensive little tester made specifically for that purpose, such as our #01950 Tractor Plug Output Tester. See this and/or buy it in our product store section.

Why is the battery not included?

Two reasons: First, batteries are considered Hazardous Materials; the parcel companies won’t accept them for shipment. That leaves shipping via motor freight; the cost is prohibitive. Second, there are different types and sizes of batteries available, and their characteristics vary. No one battery will suit everyone’s needs. See Selecting the Battery.

Why don't these units come with one of those specialized rechargeable batteries?

Because these batteries are specialized, they are only relevant in certain applications, and they aren’t widely available. Sooner or later any battery will require replacement. When that day comes, you will be able to buy a replacement battery inexpensively and with a single phone call to your usual battery supplier; you’re not tied to us for your battery. Ten years from now this equipment will still be in use every day, not forgotten in a dusty corner waiting for someone to track down a specialized battery. If you haven’t already done so, see Selecting the Battery.

What kind of battery do I need?

Snecanr, RVCHECK, and Checkmate 1200 and Checkmate 1200-A are not fussy about the battery you install. You have the ability to select the size and type of battery with those specific attributes that are most relevant to your intended usage. Express Garages require a specific size (Group 22NF) battery. For detailed battery selection suggestions, read Selecting the Battery.

Do I absolutely need a battery?

No, not for your Scanner, RVCHECK, Checkmate 1200 or Checkmate 1200-A, but whatever power supply you use it must meet two requirements: It must be capable of producing 30 amps or more into a dead short, and its output must be filtered to work properly with electronic equipment. Using a regular shop battery charger alone to power either unit is specifically not recommended. Square Wheel offers the 6 Amp Deltran Battery Tender for battery maintenance and the stand-alone 30 amp IOTA DLS-30 Power Supply. These two units differ greatly in their application, so read Power Supplies and Battery Chargers for details and suggestions regarding selection.

The Express Garage must always have a battery. This is because anytime the charger is plugged in its steel cabinet goes to “earth ground” for safety, seriously degrading the performance of the radio remote control. The remote will work well enough that you can operate the air controls from the front of the trailer, but in order for the remote to operate dependably from the rear of the trailer (which is the whole point of the remote), you’ll need to operate on battery power.

What is the best way to connect my charger?

We recommend charging your Scanner, RVCHECK or Checkmate’s battery through its 7-Pole Plug. Other options are using your service truck’s charging system, or through a direct connection to the battery. Read Connecting Your Charger for details. The 6 Amp Deltran Battery Tender can be installed inside your tester’s carrier next to the battery and be permanently connected.

The Express Garage comes equipped with its own built-in battery maintainer, so no connection is ever necessary.

What if my light tester stops working?

All Scanner, Checkmate 1200 and Checkmate 1200-A, and RVCHECK testers are covered by a comprehensive 5-year 100% warranty (none of that pro-rated stuff); read Warranty for the details. The Express Garage and Express Mobile have a One Year 100% Warranty. Off-Warranty repairs and spare parts are available.

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