Wiring Harness Questions
Wiring Harness Questions I've been reading and searching and reading. My brain hurts. This is what I have...
Engine:
2008 aluminum 5.3 (58x reluctor and side knock sensors) with DOD and VVT. (both deleted)
I have a 3 bolt cam with 4x timing gear.
I'm using a truck intake for the time being. (adding S/C later)
Car:
57 Chevy sedan with manual transmission (Ford T5)
Now for the questions...
I am going to look at a wiring harness with 3 connector E78 ECM tonight from a 2011 Silverado 4x4. It's complete with accelerator pedal and fuse box. How hard is going to be for me to delete the unnecessary 4x4 and auto trans wiring and logic from this setup?
Do I need a vehicle speed sensor for any reason?
There doesn't seem to be a lot of info out there on the later model harnesses and ECMs. Any links or additional info I might need to know heading into this would be greatly appreciated.
Thanks
Engine:
2008 aluminum 5.3 (58x reluctor and side knock sensors) with DOD and VVT. (both deleted)
I have a 3 bolt cam with 4x timing gear.
I'm using a truck intake for the time being. (adding S/C later)
Car:
57 Chevy sedan with manual transmission (Ford T5)
Now for the questions...
I am going to look at a wiring harness with 3 connector E78 ECM tonight from a 2011 Silverado 4x4. It's complete with accelerator pedal and fuse box. How hard is going to be for me to delete the unnecessary 4x4 and auto trans wiring and logic from this setup?
Do I need a vehicle speed sensor for any reason?
There doesn't seem to be a lot of info out there on the later model harnesses and ECMs. Any links or additional info I might need to know heading into this would be greatly appreciated.
Thanks
Also...Is there any reason I would not want CAN BUS capability?
And, is there any reason (or possibility, given the 58x crank sensor) that I would want to use a 1x cam gear/cam sensor and an older harness/PCM?
And, is there any reason (or possibility, given the 58x crank sensor) that I would want to use a 1x cam gear/cam sensor and an older harness/PCM?
For a 57, Id recommend dumping the OEM harness and getting an aftermarket one. E38 or E67, doesnt matter. The truck harness is massive and wont fit the 57 engine bay very well
Be aware the E38 can have analog gauge outputs, where E67 must be CAN-BUS. Something to keep in mind when you order gauges
Yeah it more expensive up front but for a nice conversion, its very helpful from an install perspective and aesthetics
Be aware the E38 can have analog gauge outputs, where E67 must be CAN-BUS. Something to keep in mind when you order gauges
Yeah it more expensive up front but for a nice conversion, its very helpful from an install perspective and aesthetics
For a 57, Id recommend dumping the OEM harness and getting an aftermarket one. E38 or E67, doesnt matter. The truck harness is massive and wont fit the 57 engine bay very well
Be aware the E38 can have analog gauge outputs, where E67 must be CAN-BUS. Something to keep in mind when you order gauges
Yeah it more expensive up front but for a nice conversion, its very helpful from an install perspective and aesthetics
Be aware the E38 can have analog gauge outputs, where E67 must be CAN-BUS. Something to keep in mind when you order gauges
Yeah it more expensive up front but for a nice conversion, its very helpful from an install perspective and aesthetics
In other news...I dropped my heads off at Noland's. I'll drop off my block at Mann Speed Specialty in a few days, so... the mechanical aspect is starting to come together.
Teching In
Joined: Apr 2017
Posts: 22
Likes: 0
I have a L96 6.0 / 6l90 with E78 ecm out of a 2500hd truck
This now in a 1956 3200 Longbed Chevy.
Note the E78 is a rare bird among many. only in a few year models and only in the big trucks and cruize. So many of the tuners have NO bench harness or prebuild mods.
So as posted above pay now for the new harness e38 combo or pay often for license for tunes.
I opted for stock harness since i have room in truck bay. Never even un plugged it from engine just wrapped up unneed sockets just incase I want them in future. needed 4 wires to stock fuse box to power up. I went ahead and spent the money on hptuners so I would hold the license for my ECM without worry of switching tune guys.
if you are going original gauges note the speedo is going to be your issue. If your tranny has outputs your good if you can go manual from tranny your good. if you use the newer trans you will need can bus. The e78 make sure you turn off the starter diagnostic along with the normal VATS / 02 etc. the starter diagnostic will cause no fuel via the injectors. soon as I disabled that she fired right up.
This now in a 1956 3200 Longbed Chevy.
Note the E78 is a rare bird among many. only in a few year models and only in the big trucks and cruize. So many of the tuners have NO bench harness or prebuild mods.
So as posted above pay now for the new harness e38 combo or pay often for license for tunes.
I opted for stock harness since i have room in truck bay. Never even un plugged it from engine just wrapped up unneed sockets just incase I want them in future. needed 4 wires to stock fuse box to power up. I went ahead and spent the money on hptuners so I would hold the license for my ECM without worry of switching tune guys.
if you are going original gauges note the speedo is going to be your issue. If your tranny has outputs your good if you can go manual from tranny your good. if you use the newer trans you will need can bus. The e78 make sure you turn off the starter diagnostic along with the normal VATS / 02 etc. the starter diagnostic will cause no fuel via the injectors. soon as I disabled that she fired right up.
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I have a L96 6.0 / 6l90 with E78 ecm out of a 2500hd truck
This now in a 1956 3200 Longbed Chevy.
Note the E78 is a rare bird among many. only in a few year models and only in the big trucks and cruize. So many of the tuners have NO bench harness or prebuild mods.
So as posted above pay now for the new harness e38 combo or pay often for license for tunes.
I opted for stock harness since i have room in truck bay. Never even un plugged it from engine just wrapped up unneed sockets just incase I want them in future. needed 4 wires to stock fuse box to power up. I went ahead and spent the money on hptuners so I would hold the license for my ECM without worry of switching tune guys.
if you are going original gauges note the speedo is going to be your issue. If your tranny has outputs your good if you can go manual from tranny your good. if you use the newer trans you will need can bus. The e78 make sure you turn off the starter diagnostic along with the normal VATS / 02 etc. the starter diagnostic will cause no fuel via the injectors. soon as I disabled that she fired right up.
This now in a 1956 3200 Longbed Chevy.
Note the E78 is a rare bird among many. only in a few year models and only in the big trucks and cruize. So many of the tuners have NO bench harness or prebuild mods.
So as posted above pay now for the new harness e38 combo or pay often for license for tunes.
I opted for stock harness since i have room in truck bay. Never even un plugged it from engine just wrapped up unneed sockets just incase I want them in future. needed 4 wires to stock fuse box to power up. I went ahead and spent the money on hptuners so I would hold the license for my ECM without worry of switching tune guys.
if you are going original gauges note the speedo is going to be your issue. If your tranny has outputs your good if you can go manual from tranny your good. if you use the newer trans you will need can bus. The e78 make sure you turn off the starter diagnostic along with the normal VATS / 02 etc. the starter diagnostic will cause no fuel via the injectors. soon as I disabled that she fired right up.
I'd love to see a few pics of your rig!
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Registered User
Joined: Feb 2019
Posts: 3
Likes: 0
E78 pcm I have a L96 6.0 / 6l90 with E78 ecm out of a 2500hd truck
This now in a 1956 3200 Longbed Chevy.
Note the E78 is a rare bird among many. only in a few year models and only in the big trucks and cruize. So many of the tuners have NO bench harness or prebuild mods.
So as posted above pay now for the new harness e38 combo or pay often for license for tunes.
I opted for stock harness since i have room in truck bay. Never even un plugged it from engine just wrapped up unneed sockets just incase I want them in future. needed 4 wires to stock fuse box to power up. I went ahead and spent the money on hptuners so I would hold the license for my ECM without worry of switching tune guys.
if you are going original gauges note the speedo is going to be your issue. If your tranny has outputs your good if you can go manual from tranny your good. if you use the newer trans you will need can bus. The e78 make sure you turn off the starter diagnostic along with the normal VATS / 02 etc. the starter diagnostic will cause no fuel via the injectors. soon as I disabled that she fired right up.
This now in a 1956 3200 Longbed Chevy.
Note the E78 is a rare bird among many. only in a few year models and only in the big trucks and cruize. So many of the tuners have NO bench harness or prebuild mods.
So as posted above pay now for the new harness e38 combo or pay often for license for tunes.
I opted for stock harness since i have room in truck bay. Never even un plugged it from engine just wrapped up unneed sockets just incase I want them in future. needed 4 wires to stock fuse box to power up. I went ahead and spent the money on hptuners so I would hold the license for my ECM without worry of switching tune guys.
if you are going original gauges note the speedo is going to be your issue. If your tranny has outputs your good if you can go manual from tranny your good. if you use the newer trans you will need can bus. The e78 make sure you turn off the starter diagnostic along with the normal VATS / 02 etc. the starter diagnostic will cause no fuel via the injectors. soon as I disabled that she fired right up.
Teching In
Joined: Apr 2017
Posts: 22
Likes: 0
If you plan on doing multiple cars and/or multiple flashes and tunes spend the money on tuning software/hardware. That way you have control of the keys and product. You can send it to tune guys or they can send you their tune and you can flash it yourself as many times as you need to.
Teching In
Joined: Apr 2017
Posts: 22
Likes: 0
ok then I just pulled in the current setup of the ecm and tcm. downloaded the vats updates from hp.
turned them off. Make sure you turn off the starter diagnostic.
It took me a while to find that one. otherwise it will not fire. I then made sure all the right data points for gear ratio, Fuel pressure etc matched the current truck. Fired it up and drove it for a couple of months before touching anything else. had no issues. What is your donor out of?
turned them off. Make sure you turn off the starter diagnostic.
It took me a while to find that one. otherwise it will not fire. I then made sure all the right data points for gear ratio, Fuel pressure etc matched the current truck. Fired it up and drove it for a couple of months before touching anything else. had no issues. What is your donor out of?
Registered User
Joined: Feb 2019
Posts: 3
Likes: 0
ok then I just pulled in the current setup of the ecm and tcm. downloaded the vats updates from hp.
turned them off. Make sure you turn off the starter diagnostic.
It took me a while to find that one. otherwise it will not fire. I then made sure all the right data points for gear ratio, Fuel pressure etc matched the current truck. Fired it up and drove it for a couple of months before touching anything else. had no issues. What is your donor out of?
turned them off. Make sure you turn off the starter diagnostic.
It took me a while to find that one. otherwise it will not fire. I then made sure all the right data points for gear ratio, Fuel pressure etc matched the current truck. Fired it up and drove it for a couple of months before touching anything else. had no issues. What is your donor out of?
Teching In
Joined: Jan 2022
Posts: 14
Likes: 1
From: Upstate NY
I'm swapping a l96 / 6l90e with a e78 ecm into a volvo wagon. I'm looking for any info on the engine harness. I 've got the pinout for the ecm connections, but I'm struggling to find any info on the pinout to the body wiring for the DBW and odb2 connections. Any suggestions?
Teching In
Joined: Jan 2022
Posts: 14
Likes: 1
From: Upstate NY
2011 2500hd silverado. I'm trying to modify the stock harness and pare it down to the 4 inputs.
I think you may have been the only guy on the internet that actually got his e78 to work! ( or at least the only that posted it, LoL)
I think you may have been the only guy on the internet that actually got his e78 to work! ( or at least the only that posted it, LoL)