Holley Sniper EFI harness routing

[vtullomk4]

I have the Holley and Ron Francis wires roughly laid out in my MK4 engine bay to connect the various wires and sensors I have a Blueprint 347. I am struggling to find a clean routing. Please give me suggestions on where to run the 3 harnesses, mount the relay/fuse, etc. Should I run some across the manifold and others along the L/R frame tubes? Want to hide as much as possible or look clean. Thanks.

Vince

[TMartinLVNV]

I have the relay and most of the wiring in the back corner on top of the right footbox. It is well hidden back there. I guess you could see it if you were to put your head in the engine bay to look under the body :rolleyes:

The power/ground wires are going directly to the battery. In my case, I have the Breeze battery box in the RF corner of the engine bay. They are routed along the middle right side tube with the inline fuse just a few inches away from the battery. I wrapped the wires in heat reflective tape where they run above the headers. Most of the wires are run along the back lower portion of the firewall from the Sniper to the top of the left footbox. Of course, you will also have a few running through the pass through grommets to connect to the RF harness.

[vtullomk4]

Thanks. Did you run the alternator and coil wires over the manifold or down the side before crossing over?

[vtullomk4]

Any pictures of harness routing and installs will be ppreciated.

[Papa]

As Terry said, most of the ugly stuff is tucked back in the corner of the passenger footbox. For the wires running to the coil and alternator as well as the temperature control sensor wires and tach wire, I ran them through wire loom to hide as much as I could. It could be cleaner ...

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[TMartinLVNV]

Thanks. Did you run the alternator and coil wires over the manifold or down the side before crossing over?

They are actually going through the manifold on mine. I covered them with wire loom first. I have the Edelbrock Air Gap manifold. So I can run the wires under the intake runners to hide them. On a regular manifold, you can run them in the valley between the intake and the head.

[RBachman]

I have the coil on the PS manifold and a Breeze battery box up front.

My main goal was to prevent electrical interference. So the distributor wires are run along the passenger side manifold, and the coil wires are run along the DS manifold. Power is run along the front light/fan harness directly to the battery. Other than those, if they came out of the Sniper, then I figure they can run together. Otherwise there is some distance made between, parallel runs are reasonable avoided, and they only cross at/near a right angle. The breather hides most of the wiring in the valley.

Here are a few "might-as-well" things that might help you out in the long run:
Use the Holley to control the fuel pump and the fan.
Add a SPST switch in series with the emergency fuel shut off switch. This will help prevent theft and allows you to shut down the fuel pump manually. This switch will also take the circuit to ground, making it easy to install a small confirmation lamp.
Add a high temp warning light by the Temp Gauge. The second fan trigger wire from the Sniper can be used to take an LED to ground if the temp gets too high. You can set this temperature with the Sniper.
Add a light to let you know when the pump is energized. This can be triggered by the Sniper or by simply connecting it to the fuel pump wiring.
Add an electronic fuel pressure gauge. Speedhut can provide one that's the same style you have now.

Here's an older picture of how mine is mounted, although it was covered with sanding dust when taken. 142897

[Norm B]

I had a RF issue with my original wiring and Holley had me move the coil to the F panel and route its wiring back along the manifold and then forward along the foot box to the front. It is taped to the brake booster vacuum hose. The Hyperspark distributor wires run up the manifold and are protected and shielded with loom.
The power wires run to the back and down the passenger side frame to the forward mounted battery. You can see the fuze attached to the firewall to the right of the heater.

HTH

Norm

[BradCraig]

Agree with the RFI mitigation statements from Richard. Before you drill holes and permanently mount the harness, temporarily secure and make sure everything is good given you may need to move some stuff around. RFI and the Sniper ECU can be problematic. If you don't already have one, I recommend getting a USB\CAN cable so you can connect to your laptop and tune via the Sniper software.

[vtullomk4]

Thanks for the input. I ran the alternator cable under the manifold to the alternator. I ran the 7 pin harness to the passenger foot box. The relay and fuse will be mounted there. The power wires run directly to the battery.

Fuel pump wire (blue) and 12v switched wire are plenty long to connect. But the yellow wire for the coil (with a ringed terminal) is very short. Did I mount the harness wrong or can I just extend the coil wire and route it thru the manifold as well?

Thanks for your patience. I want to get this right.

Vince

[Papa]

Thanks for the input. I ran the alternator cable under the manifold to the alternator. I ran the 7 pin harness to the passenger foot box. The relay and fuse will be mounted there. The power wires run directly to the battery.

Fuel pump wire (blue) and 12v switched wire are plenty long to connect. But the yellow wire for the coil (with a ringed terminal) is very short. Did I mount the harness wrong or can I just extend the coil wire and route it thru the manifold as well?

Thanks for your patience. I want to get this right.

Vince

You can extend it to reach the coil (-) post.

[vtullomk4]

Picture of harness I have attached. 143013143014