Walkthrough: replace wagon wire harness

Like some others on here, I ran into the "wagon rear wiring harness eventually wears out and wires break" issue. First noticed it with a non-working rear wiper, which I soldered, but saw several other wires getting close to dying (insulation had already cracked, bare wires exposed).

 

So, I ordered a replacement part 81812AG03B from Fred Beans for around $70-80. Took 1.5 weeks to arrive, but otherwise ok. The harness has like 14 connectors and 15 clips on it.

 

Someone in the original "Wagons beware - tailgate electricals" thread asked me to do a walkthrough, so here's my first walkthough ever. I'm going to split it up into a bunch of posts to make managing the pictures easier. Hope you like it

We start with a stock WAGON tailgate. Note, the harness we're replacing is on the PASSENGER side, NOT the driver's side. This harness includes things like rear gate light, rear wiper, backup lights, gate locks, etc. If any of those aren't working, take a look inside the rubber accordion for broken wires.

 

First things first: remove the negative battery connection, just to be safe. Or at least turn off your rear gate light..

 

We start by using a flathead screwdriver to pop the trim piece off as shown - passenger side, gate side trim. Pry up, it's all clips, and will pop up. Repeat on other side (I did it later on, but you'll need it eventually need to take it off anyway).

Next, we work on the middle gate trim piece. Again, just use a screwdriver (or your fingers) to pry it loose - 4 plastic clips. You'll see a bunch of wires exposed already.

 

The 3 red circles in pic #2 (look closely) are for clips/connectors you'll eventually remove/replace.

 

The 4 blue circles are ones you need to keep clear for the center trim piece to be re-attached later. I highlight this because these holes are interchangeable, and I accidentally put one of the harness clips into a blue hole and had to switch it to get my trim to pop back on. Luckily, it came out easily - the plastic clips won't all come out so easily. Where possible, reach behind the hole and squeeze the clip from behind to release it. It will save you a bunch of yanking with pliers. Not all clips are accessible this way, though, and some will require pliers.

 

 

pic 3 - comparing the original harness and the new one, to make sure they are the same. Note: new harness had a bigger ground ring with 2 wires attached, not just one, as the original piece. Guess they updated something over time.

Now, use the flathead to pop off the trim on the car itself. Same idea - 3 plastic clips, easy to remove, easy to push/punch back on.

 

Pic #2: here's the harness coming down from the roof. It goes just a few inches below where it disappears.

Next, we have to loosen the headliner. This is something I'd never done on any car, so I was just a bit nervous. There's a back trim piece held on by metal self-locking clips (not sure what the right name for these is) - they hold the trim piece ONTO the headliner.

 

The headliner itself is held in place by other clips - 3 of these bigger plastic clips (pic #2). The clips slide out - remove and save. I didn't, and had to spend 10-15 minutes at the end hunting for a couple of them.

 

Pic #3: view inside the headliner. One connector goes to the rear interior light.

 

Pic #4: plug removes relatively easily. I think all of the plugs have some kind of retaining clip or tab that has to be pushed out of the way before you can unplug - so always look at the new harness for where the clip or tab is and how to best remove the plug.

 

Pic #5: you'll need a ratchet with a Philips #2 or some other kind of very short Philips or something. The screw is actually angled a bit towards the back and was a real pain to remove.

Next, I removed a couple of screws from the trunk trim/cladding in order to access the lower end of the harness and get a good look at what I was getting into.

 

Note the screw inside the tie-down hook (pic #2).

 

At that point, with a bit of pressure, you can loosen a few plastic clips holding this trim piece and you can see what's going on inside (pic #3). See the 3 white plugs that need to be removed/replaced. Start with the one closest to you, then the next, then the last one. If you do this right at the end with a bit of slack in the wires, it will be a bit easier - the connectors will spin/swivel so you can get a better look at the retaining tabs.

At this point, we need to remove the full gate trim piece in order to get access to all the remaining connectors. This seems a bit intimidating at first, but really isn't that bad. The side trim pieces on the gate have already been removed.

 

There's a cover inside the handle used to pull the gate closed - pop off the lid (pic #1), remove the screws.

 

There are bunch of plastic nails/screws with a pan head on top that hold the trim in place - 6 in total. 2 are already exposed, where the side trim went - remove those.

 

Now we need to remove some more trim to get at the last 4. Pic #2 - pull sideways, and for most of them, the clips STAY inside the rubber piece. However, it's not hard to later pull the clip and put it back into the rubber piece. This exposes 4 plastic "nails" you'll need to pull.

 

At this point, the whole thing should come off. However, there are 5 internal plastic clips as well. 4 are easy to spot in pic #3 - they are white. One is green, and not so easy to spot - it's near the wiper motor (bulge in the trim).

Here's a shot of what the gate looks like from the inside with the trim removed - note: at this point, I was starting to worry about a sunburn, so trying to stay inside the car as much as possible

 

At this point, you've exposed all the wiring that needs to be exposed. Gently unplug the old harness, remove any clips, replace with the new wire. I didn't push in mounting clips until I had re-connected everything and given it a quick test (backup lights, rear gate light, rear wiper).

 

Once I had the top replaced, I went and removed the bottom connectors, and removed the old harness entirely. At this point I realized I might have made a tactical mistake, but it turns out it was not a problem: you can slide the bottom half of the harness through the top gate access hole to come out the bottom gate access hole, and then into the top body access hole, and out the bottom body access hole. It's nice that the according has "body" and "door" on it to show you which way the harness goes.

If you're happy with your quick test, push in all the wire-clips to secure the wires. <Haynes manual> re-installation of the trim is the reverse of removal </Haynes manual>.

 

First step - re-install the 2 screws you removed from the trunk liner close to where the harness plugged into the 3 plugs near the taillight.

 

Next, put the trunk piece back on and secure with the 4 bottom plastic nails. Push firmly on to engage the internal clips until the trim is snug against the glass window part - there should only be a very small gap. Put in the other 2 nails.

 

Reattach the rubber trip. Screw in the two handle screws. Trunk main trim is done.

Re-install gate side trim - it just pops back on.

 

Now, you'll need to re-attach the headliner. Don't be afraid to pull the headliner down 6-8 inches at the back - I was unable to firmly attach the back trim piece without doing so.

 

Re-attach the trim piece using the metal clips as shown.

 

Re-insert the black clips into the headliner frames for them. Pop headliner back into place.

 

Pop middle gate trim piece back into place.

 

Pop side gate trim pieces back into place.

 

Voila!

Ok, a little quicker at the end, but hopefully you get the idea. Also in a bit of a hurry - please excuse any typos. Feel free to ask any questions!

Brilliant walk through, thanks. I was shaving trouble getting the rear pillar covers off and was too sacred to try due to risk of breaking clips. Any replacement part here is New Zealand is EXPENSIVE, even from wreckers (dismantlers, junk yards, not sure what you call them) - if you can find the part.

 

I'm also about to mod (or at least try to), my reversing light into a row of cree LED's. Last time I took off the tail gate cover was 3 or so years ago to put in a reversing camera, I recall having fun getting the plastic panels off. So it's a good refresher. If the light idea works I'll try a guide too. I shoudl add, I have a JDM version, so only one of the lights is reverse, the other is a fog light. I already did the basic (so called) cree LED and it was better but still poor.

Awesome walkthrough. Thanks for doing this.

 

Is there anything you did to the harness before putting it in to make it hopefully last longer?

Awesome walkthrough. Thanks for doing this.

 

Is there anything you did to the harness before putting it in to make it hopefully last longer?

 

Glad to help - other's walkthroughs have saved me countless hours and $$. I felt like giving back a little.

 

No, I didn't do anything to the wires. The car's 10 years old - I only expect to need another 5 years out of this harness..

Thanks for the walkthrough Hadvw! I'll no doubt need this eventually.

 

Please make sure that you document and report this to http://www.nhtsa.gov as this issue can result in brake light failure. Also, make sure you save the receipt for the harness or print it out in case this is ever issued as a recall.

hadvw,

 

Thanks for the walk-through on how to install the wiring harness. I just noticed that you listed 81812AG03B as the part number and as per Subaru, this is a part number for the LGT Sedan and not the wagon. They said the correct part number for the wagon is 81812AG03A. Can you confirm this? The price for 81812AG03B is significantly more expensive than the 81812AG03A (81812AG03B - $194) Thanks in advance!

 

BTW, I have a 2005 Legacy GT Wagon 5EAT

Ok, first, I'm not an expert. I will say that "B" worked for me. Putting the part number into google brought up various Subaru links, including the one that describes this part, and the "A" and "C" variants. Here's what I saw:

"A" is listed for "21 vehicle variants", all 2005

"B" is listed for "42 vehicle variants", 21 each for 2005 and 2006.

"C" is listed for 2007-2009, so clearly not relevant.

 

Not sure if everyone knows by now, but it's not "secret" by any means, that there were 2 2005 5EAT version. The early release that had (I think) an extra gas tank pressure sensor or something, and the later release. The later release is also known as 2005.5 by some - I think Cobb introduced this notation (or maybe not).

 

So here's my guess:

"A" is for 2005 models, both 5MT and 5EAT

"B" is for 2005.5 5EAT models, and all 2006 models. I don't know if there were any differences for 5MT between 2005 and 2006, so perhaps either one fits?

 

I know I have a 2005.5, and I got "B", and it was an exact replacement for what I had.

 

Do you know if you have an '05 or an '05.5? You may need the "A" if you have an '05. Or you might get away with a "B", but I have no way of knowing.

I have the 2005 earlier release it seems like.

 

Thanks, hadvw!

Reverse lights on my wagon just stopped working so I will be looking at this. thanks for your writeup!

Just to confirm, 81812AG03B is the right part for 2005 LGT 5 MT wagon, I pulled trim in cargo on the right side and there is a sticker on it with pn. Cheapest I could find was $65 with some shipping. will call tomorrow to check on how much time it will take to get the part, if too long will repair original harness.

So, I just got the A and B parts and looks identical except for one ring for ground.

Thanks for this walk-through, it is giving me some confidence in pulling off the job!

 

I ran into a little snag already -- while pulling off the driver side gate trim, it broke. Guess some of those tabs are stronger than the trim plastic or I pulled at a bad angle. Whoops!

I replaced the harness couple of days back and first of all want to thank OP for this great writeup. definetily saved a lot of time following this rather than probing in the dark!

 

Wanted to add couple of notes based on how it went with my wagon:

 

1. I found that it is not necessary to separate rear plastic trim from the headliner. The headliner is held in place by 5 plastic clips - 3 in the back, and two other ones - one on each side further in. Here are the original pictures:

 

http://legacygt.com/forums/attachment.php?attachmentid=204159&d=1425766068

 

and clips:

 

http://legacygt.com/forums/attachment.php?attachmentid=204160&d=1425766068

 

 

 

These are the pictures I made showing same rear clips and two side clips that easily come out and allow head liner to be lowered enough to reach all the harness connectors and clips easy.

 

http://legacygt.com/forums/attachment.php?attachmentid=218876&d=1446086764

 

Side clip:

 

http://legacygt.com/forums/attachment.php?attachmentid=218874&d=1446086764

 

and the other side clip:

 

http://legacygt.com/forums/attachment.php?attachmentid=218875&d=1446086764

 

Second - on reaching those white clips under the roof top. Boy what a PITA to get those out. I used my HF trim tools set (well worth $8 it costed me) to get those out, REAL PITA. Just have patience and work them out.

 

Third - when trying to disconnect rear glass heater connector be patient, there is a little black tab in the middle connector, depress it and then the connector comes off the heater connector. Don't yank or pull that harness connector too hard- the glass side contact can be broken off, don't want to even think how to get that repaired.

 

That's all and once again thank you for great write-up!

Our wagons are at the age where a lot of people are doing this, I suspect.

 

I just finished up the job. Got held up for a long time trying to disconnect the middle (of three) electrical connector on the right hand pillar near the tail light. My solution was to pop the fastener from the body of the car to get a better grip. I gave up on trying to remove more of the lower cargo liner.

 

One more note: wear gloves when poking around the headliner. Fiberglass = painful

 

To top it all off, my rear wiper STILL won't move. Time for a motor.

So, I just got the A and B parts and looks identical except for one ring for ground.

 

Reviving old thread...

 

This is good news. I have an early build 2005 5MT Turbo wagon, and my harness PN ends with A. The B and C parts are online for $65. The A harness is $180. If I need to replace it, I'm going with B.

 

My reverse lights were out. After replacing a bad reverse switch on the transmission and still the lights didn't work, I found those 2 wires in the hatch harness were severed, and 3 more had cuts in the insulation. I put butt splice connectors on the cut wires, taped up the others, and wrapped everything in e tape. If it doesn't last, I'll get a B harness and pull it all.

 

Thank you all for posting such good info and pics!

 

-Paul