I'm laying out concept for a new engine harness. Something I can be a little more proud of this time.

I've acquired many different bulkhead connectors and the one I like the most for fit and ease of use does not have 10 AWG pass-thru for the ECM main power. Largest terminals are Deutsch DT size 16, but I have enough of those to double up with splices to the 10 AWG wires. How do you think this will work to feed main power of a Holley HP ECM? It's basically a baby Dominator without J2B, J3, J4 headers, so less power requirements. I am thinking it will be fine, but am seeking opinions.

--- Spec Comparisons ---

The Holley ECM connector: Ducon 6.3 rated at a whopping 55A
Fuse in harness: 40A
10 AWG cable: 30A continuous

Dual Deutsch size 16 terminal: 13A each, 26A combined
Dual 14 AWG cable: 15A each, 30A continuous combined

Do you think I've got the power requirements covered when considering the HP ECM doesn't have all the same +12V drivers and load potential as the Dominator?

 

part of the reason they are using a 10 AWG is also to try and limit the voltage drop... you can double check the impedance values for the base holley power set-up vs what you are proposing as a good double check

 

Yes, good point. Every connection is probably more resistance than the wire itself.

 

also you have been running the holley HP so you know in general what to expect pros / cons... i would make sure sure you do have really good connections for the power and ground as it does seem the holley is a lot more sensitive to input power disturbance, transient, etc than big GM ECM designs,

even key on / off can wipe out the program under certain circumstances (my understanding this was a design issue within their electronics vs software glitch although i haven't followed much over last couple years since i yanked mine out for the HEI reset issue)... i never had this happen to me personally, but besides just reading about it, i know someone directly who did have this happen to their wife driving a slightly rodded pick-up... when she returned to the parking lot from shopping and found it wouldn't start, wasn't too happy at all!

 

I think it happens when power is cycled off before the ECU can finish boot up. Fortunately I'm not Lightning Jack with the key switch so probably will never happen to me.

If it does happen, then I think it's possible to boot off the 3.5" display with a backup file. I don't have a display but maybe it's time to get one just in case....

 

Sounding pretty good so far.


Which TE/ Deutsch Series Size 16 Contacts are you using?
The DT Series Size 16 Contacts are Only rated for a maximum 13A Continuous load.
The DTP/ DTHD Series Size 12 Contacts are rated for a maximum 25A Continuous load.

Which Bulkhead Part Number did you go with?

 

Aaaaaah crap. I was looking at the wrong tech spec. I found the right tech spec now (108-151004).

Back to the drawing board!

 

I do not know what your budget is,but you could look at the TE/ Deutsch DRB Series Bulkheads.

Some have Size 8 Contacts (60A), some have Size 4 Contacts (100A), and some have a pass-through Studs for up to 150A Pos. Stud and 125A Neg. Stud.

The Studs can actually handle more Amperage... I do not know why TE under-rates them.

 

Fire-Wall Flanges from 48 Terminal to 128 Terminal:
Link

Housings:
Link

TPAs:
Link

I use the 102 Terminal Type with the 2 Pass-Through Studs often.

 

Yes, I have a DRB-60 in my hands. It requires very little trimming of the stock pass thru hole. I'm deep in the mind numbing exercise of mapping out pinouts.

Real estate is at a premium in that passenger kick panel. It's not as roomy as it appears at first glance because of the body seams and antenna.

 

After many Fire-Wall smoothing revisions (over many years) I have gotten to the point where I want to have these Engine-Bays...
All looking like the Engine-Bay of: @ShiftyCapone



Done this way, the Passenger Side Fender route has been closed off.

So Instead, I will be doing Dual Fire-Wall Bulk-Heads...
One on each side of the Fire-Wall.

 

Yeah, that's not going to happen.
Heck, I've never even washed the engine bay in 30 years. It's all natural under there...

 

Yeah, its awesome and it sucks at the same time. I'm am so worried about scratches and such, which is unavoidable when they aligned the car. It also financially murdered me and has prevented me from painting the outside of the car. Eventually I will.

As for bulkheads, I put a new one in right above the trans tunnel for the PSI harness and a few other gage related circuits. All nose wiring goes under the fenders and still uses the C100 and or the passenger side pass through. You also can't run a hood latch in the traditional way as I removed its pathway.

 

Use the Bulk-Head that you have...

Then also install one of these (or One in the Cabin, and a Second with a Trim Panel covering the Opening into the Engine Compartment):



A small 1/4" Version will do for your needs.

 

@QwkTrip So what did ya figure out?

 

I figured out what I had forgotten that I figured out already last year which is I don't have enough pins. It's that damn shielded cable for crank and cam using up so many pins.

So I'm doing what I always do when I need to plod a difficult path and I'm slowing down to create good documentation. Usually solutions pop off the page when I take time to think like that.

I'm making myself cheat sheets for wiring every component in the system, which is how the connectors tech thread began too..... you never know, there might be another tech thread coming out of this.

 

Okay.

So I know you have probably blown way more money on this Project than you most likely wanted...
Do you have some Cheap-O Terminal Crimpers for the following:
-TE/ Deutsch DTM
-TE/ Deutsch DT
-TE/ Deutsch DTP

???

If: "YES"
Then: I will share with you my Super Secret Solution (Not Really) for the Following:
-All above = TRUE.
-No Room for Traditional BulkHead Connectors.
-Almost out of budget, but could FUDGE One more Final Solution if it actually would work.

???

If: "YES"
Then: PM me.

 

Let's go to the back room.

 

I measured with a current meter and it was just as I suspected, very low current. ECM pulls 3.0A through the main power cable at idle and free rev.

That settles that. My dual 14 AWG splice will be overkill. I could be wrong by almost a factor of 10x and I'd still be okay.

 

Are you saying the main power feed to the ECM?
I'm putting together a Terminator system with the same cable that has a 40A fuse in it.
Also... why there is a 40A fuse in a 10Ga wire, is beyond me, but 3A seems more manageable.

There is a separate one fused at 30A for the injector & fuel pump power, plus a separate one (5A) for the trans,
The injectors typically do not draw a ton of power either.
This seemed way overkill to me & I was wondering what the actual total draw on the system was.

 

Amperage should increase for every 1,000 RPM (Engine Speed) Under load.


You will find a similar description for power draw/ consumption on Ignition Control Modules, such as the well known MSD 6AL.

 

Yes, Main Power feed (10 AWG) into ECM for Holley HP EFI with cable throttle body. I checked current on both B+ and B- near battery. I have injectors, coils, fuel pump powered through my own power center (I ripped apart the harness and got rid of all the Holley relays).

Some of the ECM power gets drawn from the +12V switched wires (18 AWG) too, so not everything is sourced from the Main Power connector.

For reference, my Racetronix 340 pump was pulling about 11.5A with same current sensor.