When an older RV has a missing or damaged oblong marker lamp, the housing may be easier to identify than the brand of trailer. Look for a 4 x 2-inch lens, mounting screws three inches apart, and an MC32 or MCL32-style body. This guide shows how to separate incandescent, three-LED and one-LED models and identify the replacement cover without guessing.
Check the original lamp footprint before choosing a replacement
Compare the surviving fixture with the outline below. Screws spaced three inches apart and a four-by-two-inch face narrow the options, but the electrical assembly must still be identified separately.
high
A practical identification checklist for older RV lighting
- Save the remaining lens or take a clear photo of the original housing and mounting points.
- Measure the front: a 4 x 2-inch oblong lens is different from the narrower 4 x 1-1/2-inch MC44 rectangle.
- Remove power before examining the rear; look for the incandescent twist-in bulb holder or count one or three LED emitters.
- Record any molded part number and compare the body depth, base colour, fastener spacing and wiring.
- For a lens-only repair, match A32ABP or A32RBP to a compatible intact MC32/MCL32/MCL0032 housing; do not use a lens to cover damaged wiring or a broken mount.
A one-LED or three-LED lamp is not a plug-in substitute for every incandescent housing. Confirm the actual power/ground configuration rather than relying on lens colour or an unverified wiring diagram.
Spot the differences between these 4 x 2-inch lights
A quick check of lamp depth can help: the MC32 incandescent housing is around 1-1/8 inches deep, while the LED families are around one inch deep. This is an identification clue, not proof of fit or wiring compatibility. The lens and base can be similar while the internal assembly differs.
| Product family | Type | Dimensions | Mounting | Electrical connection |
|---|---|---|---|---|
| MC32 incandescent | Incandescent | 4 x 2 x 1-1/8 in | Surface, 3-in centres | Twist-in socket, separate ground |
| MCL32 three-LED | 3 LEDs | 4 x 2 x 1 in | Surface, 3-in centres | Black power / white ground |
| MCL0032 single-LED | 1 LED | 4 x 2 x 1 in | Surface, 3-in centres | Two wires; power-lead colour varies |
| A32 replacement lenses | Lens only | 4 x 2 x 1/2 in | Snap-in acrylic cover | No wiring included |
Optronics published specifications: MC32 incandescent 4 x 2 x 1-1/8 in; MCL32 and MCL0032 LED series 4 x 2 x 1 in. Measurements are approximate nominal housing dimensions, not a universal fit guarantee.
Compare actual marker-light and lens listings
These products are divided by the original lamp technology. Compare the product photographs and MPN with the fixture you removed; check the individual listing for current condition and availability.
How to recognize Bulb-style MC32
If your original has a twist-in bulb holder and a replaceable #194 lamp, begin with MC32. Check the colour of the original reflex cover and whether the body was black or white. Its overall depth is approximately 1-1/8 inches; confirm clearance behind the body.
How to recognize Three-LED MCL32
A three-diode lamp with a separate black power lead and white ground lead points to MCL32. The 4 x 2-inch face resembles MC32, but the 1-inch depth and LED electronics distinguish the assembly. Compare the lens colour and base before selecting an exact MPN.
How to recognize One-LED MCL0032
A lamp with one LED behind an oval reflex cover may belong to MCL0032. These black-base versions are distinct from three-LED MCL32 models. The manufacturer's bulk and retail variants can use different lead colours; confirm the part number and connectors rather than guessing from the shell.
How to recognize A32 lens-only parts
Match the broken lens before replacing the entire lamp. A32ABP is the amber snap-in cover and A32RBP is the red version. These are components, not complete lights; inspect the original retaining lip and housing for damage before deciding a lens alone will solve the problem.
Check each UsedRVParts product listing for its condition and availability. Viewing and pickup in Kelowna are by appointment.