The tailgate lock on our 2001 Acura MDX recently started working intermittently. Sometimes it wouldn’t lock and other times it would stay locked and there was no way to open the back other than crawling into the back and using the manual unlock lever found in the little hole at the bottom center of the inside of the tailgate. I tested the lock actuator by hitching it up to a 12V source and it was working fine and cleaned and lubricated all of the rear latch components.
When I tested the voltage to the rear lock actuator it was not registering when locking or unlocking using the key fob. The issue ended up being several broken wires in the rear wiring harness. Since this is an older vehicle I didn’t want to spend the money on a new harness, so implemented a reasonably easy fix:
The first thing I did is pulled the top portion of the wiring harness cover dust cover at the top left of the tailgate. This is the exposed portion that gets flexed every time you open and close the tailgate. The top portion gets flexed the most and sure enough around and inch down 4 wires were broken and one had cracked insulation. Since I didn’t want to spend the next day locating and changing fuses, at this point I disconnected the battery.
Since there is no way to remove the dust shield without pulling all of the wires I carefully cut away with some scissors the top 2 inches, being careful to cut as little as possible to reach the broken wires and used some electrical tape to push the remainder of the dust cover as far down and out of the way as possible.
Since I wanted to leave as much flex in the wires as possible I decided to soldier the broken wires and use heat wrap insulators instead of rigid crimp quick connectors. Be sure to slide any heat wrap insulation on before soldiering the wires and have them far enough away so they don’t shrink during soldiering. I also double wrapped some of the larger wires with electrical tape.
Once the wires are fixed, wrap the cut portion of the dust cover with electrical tape, re-seat the dust grommets, reattach your battery and you are good to go. This not only fixed my lock issues, but also the rear defrost that was also a result of a broken wire.
Thanks for the info. Fixed my MDX with your info.
awsome info, that’s what i was looking for my 03 mdx
Thanks Buddy… miffed my mechanic when I did it myself because of your post!
I had the same issue. Mdx 2001. Easy fix! Thanks
My 02 quit locking….going to use this info as a starting point. Thanks from NC
Thank you Roger, I had the same problem on my 2003 MDX I checked it and found 5 wires melt
and broken. Fixed
Just wanted to say Thank you! This solved a few of my problems, and I’m so glad I came across your blog. I have 2004 MDX, rear wiper and defrost stopped working a year ago, never bothered with it, and the central locking to trunk stopped working last week. Fixed them all with this advice!
Thanks for the info. I had looked at another post earlier that wasnt as specific as to where the break occurred. It turns out that I had a broken black wire right where you said it was, on the upper left harness, an inch or two below the “dust cover”.
This was causing two problems:
1. my car would lock up if the tailgate was the only door opened
2. The interior lights would turn off if the tailgate was the only door open.
I too soldered the broken wire. But I did not cut the “dust cover”, instead i pushed the other end into the opening, thus giving me an extra inch of free wire to work with. When i was done i pulled it back out and repositioned it. Problem resolved, 2006 MDX, thanks.
PS I checked the other side for good measure and found that the same thicker black wire was also starting to break at the insulation in the same place, but wasnt yet creating an issue. So I taped that up and also taped all the wires together.
Exactly what I was looking for! Thank you for sharing!
Thanks for this! Fixed my 2001 MDX with this info.