Computer mounting location
 

Swapped in a 5.3 in the 67 GMC k10 and was curious where others mounted the computor , I would like to mount it under the drivers seat but not sure the harness will b long enough.

Re: Computer mounting location
 

You can get long harnesses.

I am going to do a 24x swap on my gen 2 LT1, and plan to put it in the corner next to the master cylinder.

Re: Computer mounting location
 

I put mine behind the glove box. I had to section the glove box liner a bit to make it fit. Standard ECM harness.

Re: Computer mounting location
 

If you have AIR, or plan to, behind the glove box will not work.
I mounted mine by the RH hinge on the firewall.
Wiring is between the fender well and the cab.
I got it to fit by loosing the inter fender screws and installing the wiring.
It isn't going anywhere because it cant.
Had the same issue dictated by a modified harness not a full on replacement.
I can be seen in the top left of the picture.
It doesn't even come close to interfering with the hood hinge operation.

Re: Computer mounting location
 

backside of the radiator support. Easy access, completely out of sight and practically no one ever notices it plus most factory GM harnesses are long enough that no lengthening is required.

Re: Computer mounting location
 

I mounted mine inside the fender, ahead of the fender liner. Basically the backside of the fender turn down that the washer bottle is mounted to...just ahead of the washer bottle. Donor harness is perfect length. Mounted the fuse box to the inner fender.

Re: Computer mounting location
 

Both good options. My harness was a Corvette and it was too short for any of the great places you both mentioned.

Re: Computer mounting location
 

I originally had intended to mount my GM ECU /ECM computer under the dash. But in the end it was so hacked up by the auto salvage yard, I was forced to look at other options. I ended up with the Holley terminator x. As it turns out , the harness has plenty of length to mount the ECU under the bench seat on the passenger side.
I ran the harness down the back side of the engine along the underside of the transmission tunnel, and up under the passenger side of the bench seat.
Just an option for those with a hacked up harness, or no harness or those thinking of hiding the ECU and wiring a bit

Re: Computer mounting location
 

i dont have stock inner fenders, but i did make some tubs. with the stock wiring i couldnt get it to reach far at all, so mine is going on top of the fender well...along with the mini fuse box and pedal box. if you had a driver side battery tray, it will fit there. almost did that but went with the fender mounting.

Re: Computer mounting location
 

I try to hide as many wires as possible. ECM and relays in the cab. In the attached pic you can just see the ECM wire loom behind the right coil cover.

Re: Computer mounting location
 

I really appreciate all the input, the more the better and unfortunately I still have the factory heater core suit case so the passenger side firewall is a no go but I do like it!!!

Re: Computer mounting location
 

clean! i dont know how you guys hide the wires like that lol

Re: Computer mounting location
 

For the LS wire harness you can pull most of the wires to the back of the engine. They will fit under the plastic coil covers.
The chassis harness to the front I ran down left frame rail.
I used used a Painless universal chassis harness. I filled the the stock fuse block hole. Then moved the Painless fuse block back a bit and then made a small hole you can't see to run the front chassis wires forward along the frame rail. The Painless wires are plenty long enough.
Here's a pic of my current 80 Camaro LS3 swap.

Re: Computer mounting location
 

very clean I think my next go round I'll will have to try something like this

Re: Computer mounting location
 

i used psi harnesses on 2 trucks. neither harness will reach under the seat,, that leaves under hood or inside cab on firewall.. i have the one on my 81 behind the glovebox
i even contacted psi about making me a harness with a longer tail..no dice..the next one i do will probably be with a bp harness.. everyone says its long enough to reach under seat..
we will see.. my next project will have a/c so i know there wont be room under dash

Re: Computer mounting location
 

I hate anything under the dash,tough for the old and stiff to access and its a tight area for tools to work in,unless your starting from scratch.

Re: Computer mounting location
 

If the wires allow it mounting the ECM between the battery and the core support works well for a lot of people. Hidden but still stays cool.
Cheers.

Re: Computer mounting location
 

Wanted to post my location. Under the dash near the wiper motor. I did use the radio mount holes but I don’t believe I will need them with my retro radio. Bear in mind this is a Holley terminator ECU but any ECU should work here.

Re: Computer mounting location
 

Hard to see but I made a mount that slides in/ out and put my behind my restomod heater/ ac box
Can get better pictures if needed

Re: Computer mounting location
 

my bp harness reached under the pass seat. nice and clean. ran the harness down the trans and up into the floor. 1971 c10

Re: Computer mounting location
 

Ideally, I would put it under a seat or console if the harness will reach.
I have a reworked factory harness that is routed off the driver's side of the motor so I put my Gen IV ecm as far forward on the inner fender as I could. It's partially hidden by the air filter.

Re: Computer mounting location
 

Got any pictures of the Terminator X mounted? At what point did you come through the floor?

Re: Computer mounting location
 

I have a couple of pics saved, the Terminator X ECU I don’t have mounted yet. It is just tucked under the seat, and the wiring harness holds it in place fairly well for now. I will most likely make a permanent mount later. I plan to remove the seat and carpet this winter and add some sound deadener/ insulation under the carpet, so the seat and carpet will come back out.
Anyway a few pics….
The first one will give you an idea of the location of the for the 2” hole required for the main harness. The power harness, I ran through an existing hole previously used for the fuel tank.
The second pic is from below, the harness was routed to the back of the engine, then down along the underside of the transmission tunnel, and up into the cab,in my case I have a high hump, I removed some of the transmission cover bolts, and replaced the bolts with longer ones, and used the longer bolts to secure both the cover and cable clamps.
The third pic is just an engine pic, but it shows how little of the harness shows, there are more ways to hide wires, but I was running out of time, and a lot will have to come back off , if I do end up doing a color change to hugger orange in the near future.
Hope this helps,

Re: Computer mounting location
 

It's been hit and more miss for me commenting on the site, you guys that are running the term x or any other Holley stuff. You should look up HCR customs Devin Vanderhoof. He builds his own LS harness. He sells Holley stuff as I believe he's sponsored by them. He is a master at wiring race cars. He uses top of the line Tesil wire. Look him up on the Tube. He puts his harness and the Holley for comparison. His is a little longer for mounting under seat. Seriously, check him out. Not trying to sell anything just like his stuff.

Re: Computer mounting location
 

Devin's stuff is top notch, I know he's a Holley vendor for sure. He's super knowledgeable and his videos are very helpful, even if you're not building a full on race car. He is also very active on the Facebook group he helps moderate.