M3-Style Side Mirror Install on the Acura CL / 94-97 Honda Accord
Introduction
M3-style side mirrors are a popular aftermarket upgrade for the first-generation Acura CL and the closely related 1994-1997 Honda Accord, swapping the factory door mirrors for a sleeker BMW-inspired housing that usually includes integrated LED marker and turn-signal lights. Because these mirrors are a universal-fit part rather than a direct OEM replacement, the job is not fully bolt-on: the supplied bracket lines up with only one factory hole, so you drill fresh mounting points, and the mirror's motor and LED leads have to be matched to the car's harness by trial and error. This guide walks through removing the stock mirror, test-fitting and drilling the new bracket, mounting the mirror, and wiring both the adjustment motors and the LED lighting. Plan for the wiring to take the most time, since it is the fiddliest part of the install. Adapted from a community writeup by klepto on AcuraZine (https://acurazine.com/forums/1g-cl-diy-faq-74/m3-side-mirrors-install-470657/), including corrections from the follow-up discussion.
Reference
Tools Required
- Electric drill
- 1/4 inch drill bit
- Flat-head screwdriver
- Phillips screwdriver
- Wire cutters/strippers
- Marker (for marking hole positions)
- Electrical tape or crimp wire connectors
Parts Required
-
Pair of M3-style side mirrors with mounting brackets and hardware
-
Six screws sized to fit the bracket holes
-
Two-conductor intercom/speaker wire for routing the LED lighting
Safety Warnings
- ⚠ Have a helper on hand, and if you are unsure of your abilities, have a professional do the install.
- ⚠ Make sure there is no gap at the top edge of the mirror base, or water can get behind it and into the door.
- ⚠ Confirm your LED signal and ground taps before buttoning up, so you do not disturb the factory turn-signal circuit.
Step-by-Step Instructions
1 Remove the interior trim panel over the mirror mount
Working from inside the door, find the small trim panel that conceals the mirror's mounting nuts and its wiring. A single clip holds it, so gently ease it away from the door until that clip lets go and the panel lifts off.
2 Disconnect the factory mirror connector
With the panel out of the way, release the stock mirror's electrical plug. Press in the locking tab to unlatch it, then pull the two halves of the connector apart.
3 Free and remove the stock mirror
Undo the three 8mm nuts holding the mirror to the door. The mirror still will not drop out, because its connector is clipped into place; reach in with a small screwdriver and press the upper retaining clip, then the lower one, and the assembly will fall free.
4 Position the new bracket and mark the holes
Take the mounting bracket that came with the new mirrors and hold it against the outside of the door. Set it so the top edge just meets the rubber weatherseal. Only the uppermost hole will line up with a factory location; while holding the bracket steady, mark the positions of the remaining holes with a marker.
5 Drill the new mounting holes
Using the 1/4 inch bit, drill out each of your marks. If two neighbouring holes merge into a single slot, that is fine, and the resulting slot actually gives you a little room to fine-tune bracket alignment afterwards.
6 Mount the mirror and fasten it to the door
Attach the mirror body to its bracket with the small screws included in the kit. Route the mirror's wiring back through the hole in the door, then secure the bracket-and-mirror assembly to the door using your own six screws sized to the bracket holes.
7 Check the fit and water sealing
Inspect the outer gaps around the new mirror. The top edge should sit tight to the body with no gap, so rain cannot track down behind the mirror and into the door. A small gap along the inner edge is normal and nothing to worry about.
8 Wire the mirror adjustment motors
Connect the three motor wires. On the driver's door the factory harness carries blue/orange, blue/green and blue/white leads, while the M3-style mirror has red, black and white leads. There are only six possible one-to-one pairings and just one is correct, so work through them by trial and error rather than mapping them out on paper. On the driver's side, one working combination paired red with blue/orange, tied black to blue/white, and sent white over to blue/green, though this left the controls mirrored (pushing left aims the glass right). The passenger door uses different wire colors, so re-test that side independently.
9 Wire the LED marker and turn-signal lights
The mirror's integrated LEDs use three leads. Send the blue lead to a parking-light circuit, the white lead to a turn-signal circuit, and the black lead to a chassis ground. A clean place to pick up the turn-signal source is the front corner bumper light: unplug its bulb holder, insert the positive and ground leads into the socket, and reseat it so nothing has to be cut. Running a two-conductor wire whose two strands have different jacket colors makes it easy to keep polarity straight along the run.
Pro Tips
- 💡 Skip mapping the wiring combinations on paper; only one of the six motor-wire orders is correct, so trial and error is usually faster.
- 💡 The driver and passenger doors use different harness colors, so do not assume the mapping that worked on one side will work on the other.
- 💡 Tap the LED turn-signal feed at the front corner bumper turn-signal socket: unplug the bulb, insert the positive and ground leads, and reseat it, avoiding any cutting.
- 💡 Use two-conductor wire with two contrasting jacket colors so you can trace polarity back without confusion.
- 💡 Elongating two adjacent drilled holes into one slot leaves room to adjust the bracket alignment.
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