For those with an LS in their truck. Cable management

[Paul Y]

Done a search but not got a definitive so thought I would ask for some advice.

My LS came with a Speartech harness which gives me flexibility on where I can mount it due to the extra length.

I want to mount the ECU in the cab - just because - and have been looking at solutions to hide the, required, big hole.

Not going to de pin and re pin as I know I will end up making a mistake so current thinking is to drill a whole - 2" or 3"? - and then use a split gromit from the likes of seal-it to hide the damage.

Questions therefore are...

Where did you drill your hole so it is hidden as best possible.

What's the smallest hole you can get away with.

Is there another option.

Look forward to hearing from those that have done.

Thanks!

P.

[MT65]

I mounted my ecu on the back of the cab, hole as you can see following the wiring , drops out and the large cable got extra protection and is running along the side of the transmission. Sorry , don’t have a picture that shows it, then it just comes up the back of the engine over the bellhousing(t-56).
Hole wasn’t terrible large, just had to feed the wire ends through carefully, no repinning anything, maybe a bit over 2”.
Not sure your cable portion is that long, I had to special order mine.

[Paul Y]

Unfortunately the harness that came with the engine is longer than normal but not long enough to put the ECU behind the seat which would have been my preferred choice.

Think I am going to put the cab back on and then decide rather than trying too do it all via guess work unless anybody else pipes up.

Like your ECU holder. Did you make it or buy it?

P.

[MT65]

Most harness builders don’t make the trunk line as long as mine, most I have found are only 4’, I have done several GM A body cars and put the ecu under the front of the console, being these trucks don’t have that, now the creativity comes into the situation. If you put in AC, that puts a bind on that side for sure. I moved my AC as far to the right as possible, so in my situation that would not work.
The ECU mount is the one from the GTO engine/transmission donor car, slightly modified, but not much…good luck with the project, you’ll get it figured out I’m sure..

Mike

[Paul Y]

Thanks Mike,

Measuring my harness there is more than enough there to put the ECU up behind the glovebox, well there would be if the HVAC was not there! No AC, yet but currently looking at making the glovebox out of folded ally sheet and then bolting the ECU to the bottom of it. In that way I still have access, it is pretty well hidden and the cable run looks to be fairly straight as I can have it coming in under the heater vents.

As I said will hang on until the cab is back on the chassis before committing to drilling holes but, at the moment the one that is used for the heater blower motor seems favourite. Well, with a little enlargement!

P.

[MT65]

This is what I made to mount the AC vents, controls and radio…as you can see on the open glove box, in my case there is a lot of stuff there in the way of a bottom mount for the ecu. Keep in mind I moved the evaporator to the passenger side, but only 2-3”. In my scenario, the best place would be high on the panel above the vent…just something to think about if your AC isn’t mounted yet.
I moved the evaporator over as my firewall is filled and I didn’t like the way the lines were designed to come out of the firewall, I used a bulkhead….

Mike

[Paul Y]

That is very nice work indeed!

Will keep you updated as things progress.

P.

[MT65]

Thank you..and please and please keep me posted….

[jweb]

On my 51 I mounted the ECU under the seat. I used one of these split grommets to deal with the large hole needed. https://www.summitracing.com/parts/s...yABEgKNUfD_BwE

I used this style of ECU mount https://www.summitracing.com/parts/n...SABEgISS_D_BwE

I plan to do the same on my 64 Suburban

[Paul Y]

Originally Posted by jweb

On my 51 I mounted the ECU under the seat. I used one of these split grommets to deal with the large hole needed. https://www.summitracing.com/parts/s...yABEgKNUfD_BwE

I used this style of ECU mount https://www.summitracing.com/parts/n...SABEgISS_D_BwE

I plan to do the same on my 64 Suburban

Thanks for the references, I have already got the split grommet in my basket but the ECU bracket, well I didn't know such a thing existed! Now also added.

P.

[MT65]

Didn’t realize that I had this picture, to the outside of the AC evaporator….the speaker is 4” ….plenty of room for ecu, depending on how you lay it out, come through firewall at top of transmission tunnel behind engine and the cable will hide pretty well and easy to layout from..

[racecougar]

I don't recall which Seals-It split grommet I used as it's been 5 years or so. I'm still quite happy with this arrangement though.