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Old 08-05-2022, 08:54 PM   #1
bcfishon
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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.
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Old 08-05-2022, 10:05 PM   #2
Ziegelsteinfaust
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Thumbs up Re: Computer mounting location

Quote:
Originally Posted by bcfishon View Post
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.
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.
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Old 08-06-2022, 04:51 PM   #3
LS short box
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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.
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Old 08-07-2022, 08:29 PM   #4
Accelo
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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.
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Old 08-08-2022, 08:42 AM   #5
Willie Makeit
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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.
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Old 08-08-2022, 05:03 PM   #6
Davidf
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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.
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Old 08-08-2022, 05:07 PM   #7
Accelo
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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.
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Old 08-08-2022, 10:19 PM   #8
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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
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Old 08-10-2022, 02:21 PM   #9
kev2809
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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.
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Old 08-10-2022, 05:12 PM   #10
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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.
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Old 08-10-2022, 05:56 PM   #11
bcfishon
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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!!!
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Old 08-10-2022, 06:22 PM   #12
kev2809
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Re: Computer mounting location

Quote:
Originally Posted by LS short box View Post
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.
clean! i dont know how you guys hide the wires like that lol
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Old 08-11-2022, 05:05 PM   #13
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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.
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Old 08-11-2022, 05:35 PM   #14
kev2809
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Re: Computer mounting location

very clean I think my next go round I'll will have to try something like this
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Old 08-13-2022, 07:12 PM   #15
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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
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Old 08-13-2022, 08:32 PM   #16
bcfishon
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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.
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