ECU Relocation Pics/Concerns

[ubertalldude]

So over the weekend I started working to move my ECU from under the passenger seat to somewhere in/on the dash. I got the wiring harness unbraided from the transmission connector and the rear-door wires, re-wound everything with electrical tape, re-hid everything going from the passenger footwell under the carpet, soldered in an extended ground wire for the ECU, and routed it out of the passegner footwell kickpanel side cover. The ECU still works and the truck runs, THANK GOODNESS!

 

Now here comes the interesting part: I want to move it on top of the dash to put it in the highest location possible, but after leaving it there for about 1/2 a day in the Florida sun with nothing covering the ECU, it got SUPER HOT. Not skin-singing hot, but too-hot-to-hold hot for sure. I don't want to do that to the computer, as it's a sensitive electrical piece. My plan to mitigate the heat is to take the black plastic cover for the ECU and paint it white, line the inside with foil, and put it on top of the ECU so nothing black or metal is in direct sunlight. That seems like my best option.

 

My question to you is if you think the white paint will be enough to mitigate the heat, or if there's a better place maybe above the glovebox inside the dash (where an airbag would usually go) that I could cut some plastic to get to?

 

[i'll be posting pics later in the day of my progress so far, and adding to the album as I get more done.]

[Citron]

There is a thread around here showing how someone mounted the ecu behind the glove box. If I remember correctly, they had to trim some of the panel that covers the ducting. They also had to heat and reshape a section of the inside of the glove box for clearance.

 

It looked like it would be hard to read codes with it in this location, so doing the remote code switch/display mod at the same time would be a good idea. There is a thread on that too.

 

I plan on doing these mods myself in the future. I am going to put it somewhere in the dash, having it on the dash doesn't seem very clean to me.

[ubertalldude]

Unfortunately pretty much any "pics" postings I've seen for the ECU relocation are devoid of active pictures due to the server space issues I've seen discussed here. I fiddled with putting it in the glovebox but am not a fan of losing that storage area.

 

I agree with you on the clean look, it WILL look awkward and misplaced, but that's fine by me. This truck is in rough shape cosmetically, and is a dedicated offroad/camping/beach rig. I just don't want to fry my ECU by leaving it baking in the Florida sun.

 

EDIT: I have found http://www.nissanpathfinders.net/forum/topic/14020-relocated-my-ecu/ this thread but my issue is that I have the old square dash '92, and I really don't like the idea of those ECU connectors still being so close to the ground, or where dirty feet could kick them! Still a good relocation, but not quite what I'm looking for.

Edited July 17, 2017 by ubertalldude

[Cuong Nguyen]

http://mississippi-mud.com/Thread-Relocating-the-ECU-Hardbody-D21-Pathfinder-WD21

 

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[ubertalldude]

that looks like a solid idea, too, Cuong. I have a different style ECU but I like that he kept his glovebox mostly intact. I'm going to see if there's any space in the dash above the glovebox that I might be able to use. Like I said, I don't care about a stock look as long as the ECU is higher and isn't getting baked by the sun (the latter is only an issue because of my placement atop the dash)

[Citron]

The Mississippi mud one is the thread I was talking about, thought it was on this forum.

 

Looking now, I see what you mean about the connections being pretty low.

 

If you find a good spot, please do a write-up.

[ubertalldude]

Having completed the ECU relocation, I thought I would share a write-up detailing how I went about it. I wound up leaving the glovebox mostly intact and placing the ECU inside of it. Nice thing about the glovebox is that the main cavity is a one-piece plastic moulding, so it's watertight until water spills in above the upper lip, whereas other ECU relocations have the connector down at the bottom of the glovebox compartment, which leaves a bit to be desired in terms of waterproofing, IMHO

 

Pics to complement this write-up: http://imgur.com/a/43clX

 

Instructions:

 

0 - disconnect negative battery terminal (ALWAYS when working on electrics)

1 - remove the passenger seat, unbolt the ECU, unbolt & unplug the connector and remove the ECU

2 - unscrew the bottom cover of the ECU with the mounting brackets and place the ECU somewhere safe, dry, and mostly dust-free

3 - cut the mounting brackets off with a cutoff wheel, or you can drill through the spot welds and knock the tabs off

4 - if you drilled the brackets off, tape the outside of the newly made holes and epoxy over them to fill them. Remove the tape after the epoxy has cured

Now you have a much more manageable size for the ECU to fit into the glovebox, and the ECU doesn't have any extra holes for debris to get into and ruin the sensitive electrical components. Back to the truck:

5 - remove the trim piece between the carpet and the door, and remove the kick panel. Peel back the carpet to reveal the wiring harness leading to the ECU. Remove the plastic shield for this harness

6 - Unwrap all that electrical tape and make sense of where the wiring harness goes to. There are essentially 3 harnesses here which are different between MT and AT models. You will need to separate them so that the ECU plug's harness is separated all the way back to the kick panel while leaving the rest of the wires intact.

7 - cut the thicker ground wire which leads from the ECU to the ring terminal. Get some automotive primary wire and solder & shrink wrap a new lead onto this ground wire. Give yourself a good 2-3 ft. of ground wire, then solder a new ring terminal onto the end for attaching to a ground point later. Reattach the old ground wire to its original location.

8 - electrical tape the separated harnesses back together, but leave the last 6-8 inches of the harness at the ECU plug end unwrapped. This is to allow some flexibility when installing in the glovebox

9 - remove the glovebox (there are 2 pins at the bottom hinge, they are tricky but can be removed by hand)

10 - remove the metal panel behind the glovebox.

11 - there is a gap between the HVAC box and the blower motor, mark the location of this gap on the rear lip of the glovebox and cut a ~1" x 1" notch in the glovebox here for the wiring to feed through

12 - At this point, you should have your ECU sized-down, your harness re-wrapped most of the way, your glovebox modified, and a new ground wire added. Now you will need to fiddle a bit to get it just right, but the essence of what you will need to do is get the ECU in the glovebox, route the wires out of the notch, temporarily install the glovebox (not the hinges yet), and shape & wrap the harness so that the wiring loom wants to curve up and out of the glovebox, thru the notch, straight down the back of the glovebox and through the gap in Step 11. Bend, tape, test fit, repeat until the glovebox will open and close smoothly without pinching the wiring harness.

13 - once you're happy with your wire wrapping and the glovebox closes freely, fasten the ground wire and fasten the lower 4 screws which previously held the metal panel behind the glovebox. (NOTE: The left screws make for a good grounding point, see pics.) Don't reinstall the plate, it is scrap metal now

14 - install the glovebox with hinges, and test that the glovebox opens and closes freely without pinching any wires

15 - route the wires through the gap mentioned in Step 12, around the back of the blower motor, and feed any excess into the kick panel area. You may want to remove the sound deadening in the kick panel to make room.

16 - reinstall all the trim pieces, carpet, etc.

 

Feel free to ask any questions or request more pics, I can always add some to the imgur gallery. Thanks for the input on the previous concerns in the thread!