Glove Box Mounting of MS and Fuse Box

[Cannonball89]

So I've been working on putting an L28ET with megasquirt into my 1971 240z over this winter. One of the things I don't like is the unfinished look of the relay board, and also the limited options for fused circuits incorporated into it. For example, I have two fuel pumps I want seperately fused, and with the relay board you can only have one fuse for a fuel pump. I'm also not a fan of the screw terminals on the relay board, I just don't think they are the most reliable connection. Basically I wanted something that is out of site yet easily accessible and easy to work on, that looks professional. Since my car has just had a big hole in the dash where the glovebox should be since the day I bought it, I figured I might as well utilize that space for the MS, fusebox, and relays. I thought there would be gobs of room, but once I placed the blower motor in place, I realized it is actually pretty tight in there, but it all fits. It's snug but it does work. So here's kind of a walkthough of how I fabricated all of this and what parts I used. I haven't really seen anybody else do anything like this, but I'm sure someone has.

 

 

 

First off, some kind of power distribution blocks are needed to use MS without the relay board. I used these 5/16 stud type blocks, available here: http://www.carshopinc.com/product_info.php/products_id/120620/406-205

 

Next I wanted at least seven seperately fused circuits, but bought a ten circuit block so I had room to add additional goodies down the road. I looked at painless wiring products but they are way too expensive. I found these on amazon for ten bucks not bad. http://www.amazon.com/10-section-ATM-Automotive-Fuse-Block/dp/B0023TIAEO/ref=sr_1_5?s=automotive&ie=UTF8&qid=1299371748&sr=1-5

 

Thats really the only specialty products I used, the rest of a couple sheets of 1/8" aluminum, lots of fasteners, and lots of wires and fasteners.

 

The first thing was make a base plate that the MS and the power distribution blocks will sit on. This is just a flat plate that has a slight bend in it towards the front to follow the profile of the dash.

 

It has to be shaped that way to clear the blower motor and the duct that comes down for the defroster. Here I mounted to MS and the blocks.

 

Here comes the hard part, making a piece to fill in the rest of the glovebox. I made this from a single sheet. This piece was VERY hard to make. I don't have a lot of tools, I just used a pnuematic cut off wheel to cut the shape then used a vice to help me bend it. I took many many hours of trail fitting and messing around before I got it to fit right. If I ever do something like this again, I think I will try to use fiberglass or something other than metal to make a piece like this.

 

Now I'm not done with that piece, it has to hold the relays and fusebox, and provide easy access to the MS and the wiring. So... It needs to be cut some more to make a door on the front of it that is hinged to allow it to fold down and also have a cut out to have access to the front of MS for the USB and SD card slot. Then a rectangular hole needs to be cut out to allow the front of the fuse box to stick out so you have access to the fuses.

 

Now I just got some small door hinges from the hardware store to allow the access panel to fold down. Here is the unit mocked up and put in place. I simply welded a small nut onto a piece of steel to hold the door up when it is closed.

 

Next up is some black paint to make it a little more incognito. I used Eastwoods chassis black. I kinda wish I had used a matte finish instead of gloss, but your only going to see it when the glove box is open so I guess it doesn't really matter.

 

Now for the fun part... reassembly and WIRING! It's really not as complicated as it looks if your not familiar with megasquirt. I probably made it a little more complicated than it has to be. This is my first time wiring a megasquirt. I don't want to discourage any newbie from buying a megasquirt because of the amount of wires. I will post a schematic of the wiring as soon as I have time to make one so you can all see the method behind my madness and possibly catch any mistakes I might have made.

 

 

Now I finally got the unit installed today and am able to start wiring the rest of the MS harness. I have bought the pre made 12' harness from DIY autotune. Overall I am very happy with how it turned out. It just took a long time and was a lot more work than I had invisioned lol but thats how most of my projects turn out. I will update with my wiring diagram and my progress later.

 

 

Thanks for reading,

Matt

[proxlamus©]

wow nice work!

[Cannonball89]

Here is my wiring diagram for the whole EFI system. I should also note that I am using a 240sx TPS. Please look over it and let me know if you see any problems. One thing I'm not 100% sure about is the way that the 1K 1/4 watt resistor hooks up to the TACH signal.

 

Edited March 7, 2011 by Cannonball89

[Cannonball89]

Here is the diagram focusing only on the glove box unit

 

[mobythevan]

Looks to me like you have the 1k resistor in correctly. Now you should put a touch screen in place of the glove box door so the passenger can tune anytime they feel like it.

[Cannonball89]

Thanks Moby, and yea that would be sweet to have something mounted in the glovebox to allow you to tune without a laptop. I bet one of those new tablets would fit nicely, like an Ipad or Android tablet... Hmmmmmmm if only I had unlimited time and resources lol

[bthomp]

hey mobythevan, if you were using a dizzy from a 78 280z, what would you change about this wiring diagram? Just out of random curiosity

 

awesome write up matt

Edited June 16, 2011 by bthomp

[Cannonball89]

One thing I learned the hard way after having wired everything up is that the CAS needs to receive power from the main relay, not the fuel pump relay as it is shown in my diagrams, so to anyone who wants to use my diagrams as a guide, please change that. Also the second diagram I posted has the main relay and fuel pump relays mislabeled, the main relay needs to have pin 86 grounded and the fuel pump relay needs to have pin 86 going to the the megasquirt.