Wiring considerations for Holley EFI systems.

[Just 1 More]

Thanks for the information.

[Grabber70Mach]

@andrewb70: Is the list for Wayteck in your first post still a pretty good starting point for ordering what's needed for a clean install of a Sniper? Looked for an email to do this, but didn't see one.

[andrewb70]

Yes, although I think the Bussmann panels are on backorder. My email is: projectgattago at gmail dot com.

[Grabber70Mach]

Thanks. I'm going to be placing my order and hopefully will get the Bussmann panel when they receive there next shipment.

[Rockbronco]

Thanks for posting this Andrew. Great information and right up on how to use the relay box. I did have one question on the unused thermal slots on the box. I know they have a plug and I think I have the right ones, but haven't quite figured out how they seal. Do they need to be installed onto a terminal for retention?

[andrewb70]

The green plugs just slide into any open cavity.

[Rockbronco]

Thought so, however, they seemed like they won’t stay too long.

[andrewb70]

They stay just fine.

[Nicko127]

Andrew, thank you for the detailed write up! Excellent info, I'm planning on using this method to install a Terminator X Stealth and HyperSpark ignition in my car. One part has me confused though, for the fuel pump relay you say you wired the blue wire into #85 pin on the relay as a ground. Not sure how different Sniper wiring is vs Terminator X, but I know on the Terminator the green wire meant for the fuel pump is a +12V outlet. If that's the case, I wouldn't be able to wire the fuel pump relay in the panel with the fans and ignition, correct? Would I have to choose an output that can be made into a ground to wire into the panel? Thanks again for all the information.

[andrewb70]

The Terminator X is a little different than the Sniper. The green wire is powered directly from the relay in the harness. You can actually power a fuel pump directly with that wire, provided the pump draw doesn't exceed 15 amps. Andrew.

[andrewb70]

The Bussmann panels have been out of stock for a while, but it looks like Waytek has them in stock again. Also, MSD just came out with this: https://www.holley.com/products/elec...s/parts/7566-4. And I think it will be an excellent alternative to the Bussmann panel because you don't need any really special tooling. Andrew

[machineguy]

Hello, all new to the forum. Where could I find a wiring diagram for a Terminator X Max kit 550-917 that pertains to the loose wires coming out of the main and transmission harness? The diagrams I have come across on the Holley website either don't show all of the wires I have, or in the case of the transmission harness, I can't see the picture clearly enough to make out what it says. Thanks.

[Rdf1]

https://documents.holley.com/199r11760.pdf
In the instructions for 550-917 look at section 11.0 for Loose Wire Engine harness section and 13.0 for transmission wiring.

11.0 for Loose Wire Engine harness section:
"The following loose wires in the main wiring harness should be connected as follows on all systems.
All of these wires come out of the harness about 40” from the ECU connectors except for the “12V Switched” wire.
[Required] +12V Switched – Color = Red/White – Should be connected to a clean +12 volt power source. Power source should only be active when the ignition is on. Make sure source has power when engine is cranking as well (check with voltmeter). Not all sources apply power when the ignition switch is in “cranking” position. This wire is located approximately 7” from the ECU connectors. DO NOT connect to a “DIRTY” source like an ignition coil!

[Required] +12V Battery – Color = Red – Should be connected directly to the battery. This powers the fuel pump and fuel injectors. This wire is protected by a fuse in a sealed fuse holder. The fuse holder is located about 18” from the ECU connector. A fuse is pre-installed (20A).

[Optional] 12V Fuel Pump – Color = Green - Used to directly power a fuel pump (+12 volt). Do not use this wire to power fuel pumps that require over 15 Amps. Refer to your fuel pump manufacturer for amperage ratings. For high current pumps, use this wire to trigger a separate relay and use larger gauge wire to feed the pump - 10 AWG is recommended. The pump that include with TERMINATOR™ systems draws less than 10 Amps and can be powered directly by this wire. The fuel pump also requires a ground wire. Run a wire from the negative side of the fuel pump. Connect it to a solid chassis/frame ground.

[Required] Chassis Ground – Color = Black – Connect to a chassis ground point that has excellent connectivity with both the engine and battery. There must be good continuity between the connection point and the battery when checked with a Digital Volt Ohm meter (DVOM). This ground should not be connected at the same location as other grounds.

[Optional] Tach Output – Color = Blue with white stripe – This wire provides a 12V square wave output and can be used to trigger a conventional tachometer.

13.0 For transmission wiring.
13.1 Transmission Wiring
The transmission harness can be used on 4L60E, 4L65E, early 4L70E, 4L80E, and 4L85E transmissions. Each connector should be labeled.
Transmission ECU Connector (J4) – Plugs into the ECU. Plugs into the last connector opposite the main harness.

Main Transmission Connector – Simply plugs into the connector on the transmission. Located on the driver’s side of a 4L80E (installed horizontally) and the passenger side on a 4L60E (installed vertically).

Vehicle Speed Sensor (VSS)/Transmission Output Speed Sensor (OSS) – Located on the rear drivers side on a 4L80E and the rear passengers side on a 4L60E.

Turbine Speed Sensor – The 4L60E does not have a turbine speed sensor. It is located towards the front driver’s side on a 4L80E. Note that a 4L70E has one internally wired, but is not connected to the Holley harness. The turbine speed sensor is not used for any calculations in the ECU, just for monitoring purposes.

Brake Switch (Gray) – Wired to the brake light switch. This must be installed to a +12V source (as most brake light switches are). This input is used to unlock the torque converter when the brakes are applied.

Ground (Black) – Connect to a good chassis/engine ground source.

[clcorbin]

Glad to help. I was beginning to wonder if people were just thinking I was crazy for posting all that information...LOL. Andrew

I can't say if you're crazy or not, but your post(s) have been VERY helpful to me at least! Thank you!

[Soundcraft]

Parallel universe. Just joined the forum and read this post. Reaffirms my decision to create a separate harness for the modern additions on my ‘64 Dodge. I used this with power off the starter stud. On a Mopar it's direct to battery. EVERYTHING is grounded to a common stud that shares the battery ground. The other deviation I did was solder every connection after crimping. I'm feeding the fuses off the main hot wire. Then separating into each circuit. One for Fuel Pressure. Two separate for two Spal electric fans. The other relays are used separately for headlight circuits with their fuses getting power from the dimmer switch. I chose to mount it under the battery tray to hide it. Theres also room for a CDI box later, but I'm using the Sniper module hid in a gutted voltage regulator box. I'm getting the pink wires power from a ballast resistor that was gutted and the terminals were commend together to have +12V across. This doesn’t change my factory wiring in case I have to run the Mopar ignition if the HyperSpark or Sniper module craps out. Thanks for sharing your knowledge on this system andrewb70. First time using one. If you have any thoughts on my setup I’m all ears. One thing being a live audio engineer for 25 years is that I like redundancy in crucial systems.