LiftMaster 10-11403M Electrical Box Cover for MGJ Commercial Operators
The LiftMaster 10-11403M electrical box cover is a replacement cover panel for select MGJ commercial operator electrical boxes. It is used when the original E-Box cover is bent, missing, badly corroded, or no longer closes properly. A missing or damaged cover can leave wiring labels, terminals, and controls exposed, which is a real service concern on commercial door operators used in warehouses, loading areas, shops, and industrial sites.
This part is best matched by the MGJ operator parts breakdown. The cover is not the same as the complete electrical box assembly, and it does not replace a logic board, transformer, limit switch assembly, or any internal wiring. The correct cover helps keep the operator enclosure complete and protects the wiring diagram and control area from avoidable damage.
Because LiftMaster commercial operators use several enclosure styles, the 10-11403M should be treated as an MGJ cover, not a universal LiftMaster cover. If the operator is an MH, HMJ, Logic 5 NEMA enclosure, hazardous-area enclosure, or different MGJ generation, verify the cover number from the diagram before ordering.
Compatible With / Common Applications
- Select LiftMaster MGJ commercial door operator electrical boxes
- MGJ medium-duty gear-reduced jackshaft operator applications that call for 10-11403M
- Replacement cover applications where the original parts diagram lists 10-11403M, K10-11403M, 10-11403, or 1011403
- Not a complete electrical box and not a substitute for 10-11420M1 or K-MGJ5023 E-Box assemblies
- Not confirmed for MH, HMJ, GH, J, H, HJ, GT, or Logic 5 NEMA enclosures unless the parts diagram identifies this cover
Features & Specifications
| Feature / Specification | Details |
|---|
| Manufacturer | LiftMaster |
| Product Type | Electrical box cover |
| Part Number | 10-11403M |
| Application | MGJ commercial door operator E-Box cover replacement |
| Compatible Operator Type | Select MGJ medium-duty commercial operators |
| Included Components | Cover only unless supplier listing states otherwise |
| Notes | Match by cover number and E-Box style |
Also Known As / Related Part Numbers
- 10-11403M
- K10-11403M
- 10-11403
- 1011403
- LiftMaster MGJ E-Box cover
- Electrical Box Cover MGJ
Technician Note
This is a cover-only part. If the electrical box itself is damaged, missing, or internally modified, look up the full E-Box assembly instead of ordering only the cover.
Before Ordering
- Confirm the operator is an MGJ model
- Confirm the original cover number or diagram key
- Check whether only the cover is needed or the entire E-Box is damaged
- Inspect for missing wiring labels or altered control wiring
- Do not use this cover to conceal unsafe wiring or bypassed safety circuits
Professional Advisory
Commercial door operator electrical parts should be installed and tested by a qualified commercial door technician. Disconnect power before service, follow the operator wiring diagram, and do not bypass required safety devices, interlocks, or monitored entrapment protection.
Product Questions & Answers
Is 10-11403M a complete electrical box?
No. It is the electrical box cover for select MGJ operator applications, not the full E-Box assembly.
What numbers are related to this cover?
Common related references include 10-11403M, K10-11403M, 10-11403, and 1011403.
Will this fit every LiftMaster commercial operator?
No. It is written for select MGJ electrical box applications. Other commercial operator families can use different covers.
Why replace an E-Box cover?
A damaged or missing cover can expose wiring, labels, and control components to damage or contamination.
Can I install this without checking the wiring?
The cover is mechanical, but a technician should inspect the operator if wiring is exposed, damaged, or modified.
