LS1 Wiring

[awhotrods]

I'm ready to run the engine harness for my LS1 conversion, trying to figure out where to run the harness through the firewall. Does anyone have pics or any advice on where to run the harness through? I'm also having a hard time finding a suitable grommet, (need 1.5" inner diameter) to protect the harness. Thanks in advance for any help!

[deadcarny]

Hi - sounds like you are planning to mount your ECM inside the car..? I chose to mount mine behind the left front fender (on the A pillar) on my 57 and avoided the biggie hole you are talking about. Only required a 1/2 inch hole to route the connecting wires to the car harness. You probably will have to consider how much length you have on that big bundle and how much visibility you want as well. Mine is really low behind the e-brake cable and hardly visible at all. Let me know if I can help with pics or..??

Have a great day.!! Dwight K.

[awhotrods]

Yes, the ECM is going under the dash.

Hi - sounds like you are planning to mount your ECM inside the car..? I chose to mount mine behind the left front fender (on the A pillar) on my 57 and avoided the biggie hole you are talking about. Only required a 1/2 inch hole to route the connecting wires to the car harness. You probably will have to consider how much length you have on that big bundle and how much visibility you want as well. Mine is really low behind the e-brake cable and hardly visible at all. Let me know if I can help with pics or..??

Have a great day.!! Dwight K.

[Tuned55]

I ran my harness thru the firewall directly behind the cam sensor and then mounted the ECM in the trunk. I used the groumet that cam inthe painless kit

[chevman57]

I cut a hole for my harness in the trans hump inspection cover. That way i didn`t have to cut a hole in the firewall, and if at a later date you decide to go a different direction you don`t have to weld up a hole. Just find another inspection plate.
Terry

[rigi]

I cut a hole in the firewall behind the right cylinder head. You can hardly see it.
The computer is mounted inside of the firewall.
http://www.57chevy.se/Project-57/Sidor/Engine_compartment_files/Media/PICT3117/PICT3117.jpg

[dlsnfl]

cut hole in Inspection cover and computer is hidden behind the
Passenger dashboard hump. Carpet hides the bundle of wires
going to the computer. But looking back it might had been
easier to hang it somewhere in the wheel well or engine
compartment.

[awhotrods]

Thanks for the ideas, anyone know where to get a grommet with 1.5" inner diameter?

[acardon]

Thanks for the ideas, anyone know where to get a grommet with 1.5" inner diameter?
You might try a large truck supply (as in 18 wheelers). :) I got a 2" grommet to go on my steering column there.

[Blt2Lst]

Try Mcmaster.com for your grommet.
They are an industrial hardware that sells to the public and they have just about everything hardware related.
Good luck with your project.

Al:tu

[DCWNeil]

Yes McMaster-Carr is the place. I buy stainless bolts when you need a few and all sorts of hardware from them. Their service is the best too. If I call by lubch I have it by the next day. Hardly ever out of stock.