Repair Parts
Square Wheel Industries testers are tough, and our warranty is the best in the industry, so why would anyone need repair/replacement parts? A great question.
We have been the industry leader for a long time and as a result, we have testers still in use that were built over 20 years ago! Millions of cycles can take their toll on even the highest quality parts like circuit breakers and switches, and while we will always provide repair services at our factory, these are easily field replaced as well.
Click on the tester product name below for which you need a part to see a complete list of the parts available.
If you prefer factory replacement, please call our support department at: 610-921-8561.
- Scanner Trailer Light Tester
- Express Mobile Trailer Light and Air Brake System Tester
- Express Garage Trailer Light and Air Brake System Tester
- RVcheck RV Protocol Trailer Light and Electric Brake System
- Checkmate 1200-A Trailer Light Tester with Ammeter
- Checkmate 1200 Trailer Light Tester
Most parts are in stock and will ship within two working days. We will contact you if there is a backorder.
Scanner – Trailer Lighting System Tester
Order # | Repair Replacement/Part |
51265 | Toggle Seal, Black |
62001 | Scanner Circuit Board – |
65014 | Switch – Toggle, SPST |
65019 | Switch – Toggle, DPDT, Center Off |
65132 | Relay – SPDT, w/Resistor |
65610 | Circuit Breaker – 10A, no bracket |
65620 | Circuit Breaker – 20A, no bracket |
72082 | Plug – SAE 7-Pole |
72093 | Cable Assy – 7-way, Scanner |
74101 | Insulator – Battery Terminal, Black |
74102 | Insulator – Battery Terminal, Red |
76144 | Test Clip – 50A, Black Handles |
Express Mobile – Trailer Light and Air Brake System Tester
Order # | Repair Replacement/Part |
51265 | Toggle Seal, Black |
60201 | Lamp – 2 in. Red |
60202 | Lamp – 2 in. Blue |
60700 | Grommet – 2 in. lamp mounting |
61106 | Circuit Breaker – 10 A w/bracket |
61108 | Circuit Breaker – 15 A w/bracket |
61120 | Circuit Breaker – 20 A w/bracket |
62001 | Scanner Circuit Board – |
63117 | Remote – 2-Channel w/Decals and Battery |
63118 | Radio Receiver – 2 Channel |
65014 | Switch – Toggle, SPST |
65019 | Switch – Toggle, DPDT, Center Off |
65028 | Switch – Toggle, DPDT |
65132 | Relay – SPDT, w/Resistor |
81109 | Regulator w/Filter, 1/4 npt |
81154 | Solenoid valve – 3-Way, 1/4 npt, 12V |
81637 | Filter – In-line, 1/4 npt |
82409 | Gauge – 160 psi, 2.5 in. |
85954 | Valve – Ball, 1/4 npt |
Express Garage – Trailer Light and Air Brake System Tester
Order # | Repair Replacement/Part |
11508 | Wheel – 8 x 2 in, .5 in axle |
11604 | Caster – 4 x 1.25 wheel, .5 stem |
16155 | Hold-down Bolt – pair – 10 in, J-type |
16167 | Hold-down – Battery Cross Bar |
31012 | Grab Handle – 12 in. Mtg Centers |
51265 | Toggle Seal, Black |
60201 | Lamp – 2 in. Red |
60202 | Lamp – 2 in. Blue |
60700 | Grommet – 2 in. lamp mounting |
62001 | Scanner Circuit Board – |
63117 | Remote – 2-Channel w/Decals and Battery |
63118 | Radio Receiver – 2 Channel |
65014 | Switch – Toggle, SPST |
65019 | Switch – Toggle, DPDT, Center Off |
65028 | Switch – Toggle, DPDT |
65132 | Relay – SPDT, w/Resistor |
65610 | Circuit Breaker – 10A, no bracket |
65615 | Circuit Breaker – 15A, no bracket |
65620 | Circuit Breaker – 20A, no bracket |
72082 | Plug – SAE 7-Pole |
72094 | Cable Assy – Express Garage |
74101 | Insulator – Battery Terminal, Black |
74102 | Insulator – Battery Terminal, Red |
76144 | Test Clip – 50A, Black Handles |
80075 | Valve – Safety – 150 psi, 1/4 npt |
80117 | Hose assy- Air Brake, Rubber, 3/8 in |
81018 | Filter – Primary, 1/4 npt |
81113 | Regulator – 2-150 psi, 1/4 npt |
81113-A | Regulator Nut |
81154 | Solenoid valve – 3-Way, 1/4 npt, 12V |
81637 | Filter – In-line, 1/4 npt |
82409 | Gauge – 160 psi, 2.5 in. |
84044 | Valve – Check, 1/4 npt |
85042 | Gladhand – Emergency (Red), 1/2 npt |
85045 | Gladhand – Service (Blue), 1/2 npt |
88013 | Switch – Stoplight, 1/4 npt |
89584 | Valve – Needle, panel mount, 1/4 npt |
RVCHECK – RV Protocol Trailer Light and Electric Brake System Tester
Order # | Repair Replacement/Part |
60114 | Lamp Assy – Panel Indicator – Red |
60115 | Lamp Assembly – Panel Indicator – Amber |
62028 | Resistor – 10 Watt, 27 OHM |
63094 | Flasher – 12V, 2 Pin Electronic |
65114 | Switch – Toggle, SPST, w/proof |
65610 | Circuit Breaker – 10A, no bracket |
65620 | Circuit Breaker – 20A, no bracket |
72095 | Cable Assy -RVcheck |
74101 | Insulator – Battery Terminal, Black |
74102 | Insulator – Battery Terminal, Red |
76144 | Test Clip – 50A, Black Handles |
82201 | Ammeter 0-20 |
Checkmate 1200-A – Trailer Light Tester with Ammeter
Order # | Repair Replacement/Part |
62028 | Resistor – 10 Watt, 27 OHM |
63094 | Flasher – 12V, 2 Pin Electronic |
65114 | Switch – Toggle, SPST, w/proof |
65610 | Circuit Breaker – 10A, no bracket |
65620 | Circuit Breaker – 20A, no bracket |
72082 | Plug – SAE 7-Pole |
72092 | Cable Assy – 7-way Checkmate |
74101 | Insulator – Battery Terminal, Black |
74102 | Insulator – Battery Terminal, Red |
76144 | Test Clip – 50A, Black Handles |
82201 | Ammeter 0-20 |
Checkmate – Trailer Light Tester
Order # | Repair Replacement/Part |
62028 | Resistor – 10 Watt, 27 OHM |
63094 | Flasher – 12V, 2 Pin Electronic |
65114 | Switch – Toggle, SPST, w/proof |
65610 | Circuit Breaker – 10A, no bracket |
65620 | Circuit Breaker – 20A, no bracket |
72082 | Plug – SAE 7-Pole |
72092 | Cable Assy – 7-way Checkmate |
74101 | Insulator – Battery Terminal, Black |
74102 | Insulator – Battery Terminal, Red |
76144 | Test Clip – 50A, Black Handles |