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Sniper switch power wire

PGreenlawMD

Jr. Member
Joined
Mar 16, 2014
Messages
114
Loc.
New Bern
I know this has been bounced around in various other posts. I just want to make sure as possible next step.

Vintage air installation is complete. Found a switched wire under the dash that is only powered in the run position, no power on crank and working fine for VA.

Now onto Sniper EFI. Everything is installed. My biggest concern in the installation was finding a switched wire that would be powered in the run and crank key positions. PO had a Carter carb which I switched to Edelbrock with electric choke. Choke worked fine so never explored the power source. My hope was that this would be the wire to hook up to for the sniper pink wire switched power source for the ECU. My concern was that this would not be the case.

Fired up the sniper and everything great until crank, and then screen goes blank and resets once key moved back to run. I understand an extremely common problem among this install.

Wife and kids are away on summer trip so no easily accessible help for testing power and Murphys law holds true.

Now I need to find a switched wire for both run and crank.
Pulled my ignition switch. Found out elec choke wire going to center stud of pigtail. No good. Two purple wires together. Green with black, green with red and red with green wires on another location. Put the switch back in before I realized I should have taken pictures. Pictures would be hard to get as this is original wire harness and nothing moves. In reality a huge f'ing mess of wiring behind the dash from multiple POs.

How to wire into ignition switch to get a switched wire for both run and crank for the sniper?

My plan was to move to painless harness this winter with new switches and gauges but after seeing the disaster behind the dash it may be time to move on with this sooner rather than later.
 
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PGreenlawMD

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Mar 16, 2014
Messages
114
Loc.
New Bern
Here are some pics
 

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PGreenlawMD

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Mar 16, 2014
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So I have red wire blue stripe, red wire yellow strip, and yellow wire (battery power wire I believe) coming into the pigtail

Above that connected to the central post is the large eye ring with the black green wire and the green wire with red stripe.

Another connection is the two purple wires

The red wire connected to the central post is the elec choke wire that I tried to use for the pink sniper switched power wire; alas only power on run but not on crank

The black wire attached to the central post I have not found its termination point yet. Rats nest of wires behind this dash.

Any help appreciated.
Even just a post about what each of the original wire harness wires do for my own edification. This is the first time I have ever pulled the ignition switch to look at it.
 

RODRIG3911

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Messages
970
Loc.
Tucson
I used to electric choke wire for my sniper pink wire... Not sure why mine is power in run and crank and your isn't, but It should be or else how would the choke work??? ..... I've read you can use the + of the coil wire, BUT you must only use it as a trigger to a Relay and obviously you'll hook up a power ground and the triggered post coming out of it to the pink wire :)
 
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PGreenlawMD

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Mar 16, 2014
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114
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New Bern
My understanding is the electric choke is default to the choke on position until enough heat increases the resistance to the passage of current to force it gradually to the choke off position. That is my limited rudimentary knowledge about electric chokes. In that situation power loss to the choke with crank would be so brief it woulnd/t matter. A whole different thread but if I am off in my understanding of the basics of electric chokes I would welcome any input to help educate me.
 

RODRIG3911

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You are right, but that happens inside the electric choke mechanism on the side of the carburetor (When you had one). It's not the power going to it that slowly loses voltage if that's what you're thinking... All I know is that's what is powering my sniper and I have power at both crank and run... Do you have a facebook acct? If you do go to "Holley Sniper EFI owners and Tech" there's a ton of knowledgeable people on there including Holley techs, that have helped me get my Sniper running.. The +coil wire as a trigger for the relay is probably your only other option other then the electric choke bro
 
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PGreenlawMD

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I understand 100% what you are saying about the electric choke should be switched power for both run and crank. The green wire with the red stripe and the black wire with green stripe are both connected to the same central post as the electric choke power wire. My understanding is that the green wire with red stripe is supposed to be switched power for both run and crank stated on other posts.
Can anyone verify if the central post on the ignition switch pigtail is switched power on for both run and crank? Might need to post that as a separate topic to see if I can get some hits.

I did just notice in the rats nest of wiring under my dash that the elec choke power wire from the ignition does have another wire spliced into it. Don't know where it ends up or what it goes to but will also have to investigate that. My understanding is that the switched power wire to the pink wire needs to be its own isolated power source.
Gone from home the next couple days so will look at that as soon as I can.

Never installed a relay that was not already pre-loomed with a wiring harness. May need some schematic help with that one if that is the route I need to take.
 

Slowleak

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Sep 12, 2013
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Georgia
You should have a pink wire going from the ignition switch to the coil. It also feeds to the starter relay. That would be hot in both run and crank.
b3c6d85f62987d209df6a5f1f6b2af4d.gif
 

Amac70

ME
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Mar 27, 2002
Messages
3,269
don't know what it originally went to but i used a red with yellow stripe wire under the dash. for my power on, it is on while cranking also. 70' wiring harness. looks like that could have been the brake warning light. that been disconnected in my truck for at least 15 years.
 

DirtDonk

Contributor
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Nov 3, 2003
Messages
47,355
That is not a factory electric choke wire. That would be a White w/black wire running directly from the STA post on the back of the alternator. And only on '73 and later EB's.
Any choke wire on the ignition switch is aftermarket and is not hot in START. There really is no reason for an electric choke to be energized in START anyway.

What year is yours by the way?

The center post (accessory and run) does not have power in START. Only in ACC and RUN.

From the factory, both the Green w/red (voltage regulator) and Red w/green (ignition coil) have power in RUN and START. But only if they're from the two specific locations on the switch. Any additional Green w/red wires (looks like you might have at least one?) are not necessarily good candidates unless they piggyback with the other one.

I see the push-connector on one wire. This is your resistor wire to the coil. Right at the switch it should be normal wire, but between that connector and the firewall (may have a matching connector) is resistor wire and not a good source for your EFI signal.
However, that same wire, if tapped into right at the switch could be a good source.
Personally though, I prefer the Green w/red wire(s) and leave the Red w/green for the ignition duties.

The Yellow is indeed power in to the switch.

Paul
 

Amac70

ME
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Mar 27, 2002
Messages
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so it looks like the red yellow stripe wire pins out in harness plug with the green with red stripe paul is talking about.
 
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PGreenlawMD

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Mar 16, 2014
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1967. I knew the choke wire was an aftermarket addition and had concerns with it not being powered on crank.

I will have to look at the solenoid again. I do not recall a brown wire on the I small terminal. This bronco has had many owners and many modifications. I would like to get it up and running just to make sure the sniper is functioning properly then bite the bullet sooner rather than later and rewire with a new painless harness
 

DirtDonk

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Usually there are two wires, and all the old relay/solenoids had at least the two small posts. Modern ones however only have the one small post for the Red w/blue START wire.
If yours has been changed out for a newer style then, this would explain the missing "I" wire.
But if an old original style, it's there. If no wire, check around for a small loose dark Brown wire tucked under there somewhere.
All Broncos had them in the harness. Whether it's in use or just hidden out of site depends on the PO and what their particular mindset was that day.

Paul
 

RODRIG3911

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Tucson
I wonder what would happen if you ran a wire from the battery to a toggle switch under your dash, then to the pick wire.... It would have power when turned on only so it could be a security feature too ;D
 
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PGreenlawMD

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I don’t know. That certainly could be an option to get it up and running and if it works well run with it until I rewire the darn thing. Put an inline fuse which could be low amp since this is just a switch to keep the ECU on. No major amp draw for the pink wire. Any one else with thoughts on this as temp fix

Would need to be careful not to bump switch with driving or engine would cut out.
 
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PGreenlawMD

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Mar 16, 2014
Messages
114
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Usually there are two wires, and all the old relay/solenoids had at least the two small posts. Modern ones however only have the one small post for the Red w/blue START wire.
If yours has been changed out for a newer style then, this would explain the missing "I" wire.
But if an old original style, it's there. If no wire, check around for a small loose dark Brown wire tucked under there somewhere.
All Broncos had them in the harness. Whether it's in use or just hidden out of site depends on the PO and what their particular mindset was that day.

Paul

It is an original style 4 post solenoid. I will explore when I get a chance. 5 hour drive after work to pick up kids at summer camp in the NC mountains and coming back tomm. Hopefully tomm afternoon will get a chance to explore
 
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PGreenlawMD

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Mar 16, 2014
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Sniper EFI is up and running.

The original style solenoid did indeed have a brown wire on the I and a green wire on the S post. The brown wire had been painted over so a little acetone revealed the true color. The green red stripe wire had also been painted over, but also been spliced to a solid green wire buried down in the wire loom so even with the acetone removing the black paint it still was not clear cut a green wire.

In the interest of time I wired directly to the battery with an inline fuse and switch than connected to the pink wire in the sniper harness.

Voila!! ECU fired up. With engine on crank the RPM readings went from stall to 150 without the sniper shutting down and restarting. I plan to leave the touchscreen module in the cab so I can see the info since I had to disconnect my temp guage for the EFI. Lots of info on the screen as well.

This was a short term fix. I did buy a relay and wiring pigtail to get this all wired up correctly; but before going through all that I wanted to make sure it would start, run, no leaks, and no major malfunctions

Initially engine ran really good; throttle much more sensitive than with carb with much less lag. After it started the learning mode it started to run much worse but I understand that is not uncommon during the learn mode/phase of this process. I will get the wiring tidy, wire in the relay and continue the learning process.

Thanks for everyones help and input. This forum is invaluable.
 
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PGreenlawMD

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114
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It has worked so far!!! Some other forums with discussions on the new throttle body EFI systems mentioned similar options although no one confirmed they had done it. It seems the most common difficulty, whether it is sniper, fitech, etc is finding a consistent switched wire that is powered in run and crank. Even the Holley sniper EFI troubleshooting states it as the most common problem in setting up the sniper.

Thanks for your input
 
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