My 68 Cougar Pro-Touring / Resto-Mod Project

[andrewb70]

Switched 12v

How... exactly...

[langleylad]

Switched 12v feed from fuse block to bus bar . Red/white connected to bus bar.

[andrewb70]

....Yesterday I noticed that the odometer on my Autometer speedo was lit up , but the key was off. The gauges are on 12v switched power , something is wrong. Also when I would turn the key to on , the fuel pump didn't turn on. But some times it would.....

If the odometer is lit up, then your "switched" 12+ is not actually switching. Meaning, it is not shutting off. It also means the ECU is always ON. If the ECU is always ON, then it makes sense that sometimes it would not prime with the key, because it is always getting power.

I would start looking at how exactly the fuse block is getting power. Is there a main relay that activates the fuse block?

Andrew

[langleylad]

Thanks Andrew

Mike

[langleylad]

You’re correct Andrew , key on 12.6v , key off 8.5v .

Thanks once again

Mike

[andrewb70]

You’re correct Andrew , key on 12.6v , key off 8.5v .

Thanks once again

Mike

No problem. Let us know what it was.

Andrew

[langleylad]

Ok , it seems that my first switched source was fine. I found a second source, wired it in and checked it. Same reading as before. Disconnected the ecu red/white , power goes away. Seems the red/white are providing power ?. Odometer light still on . I went through the Dominator install instructions/ electronic transmission wiring . It says not to hook up the ecu switched power red/white at the same point as the trans power red or back feed can occur and the engine will not shut off. These I wired in correctly at the start.

[langleylad]

I’ve decided to go through all the ecu wiring . Actually I already started. I’m going to remount the Dominator in a better location, I had it between the firewall and the heater/AC box . So I spent last night under the dash pulling everything out. Two steps forward one step back.

[frojoe]

If you'd like me to come over one day and help you go thru the wiring, I'd be happy to. I've recently redone my battery/fuel pump wiring, but I've also been refining my electrical/wiring process and mentality over the last several years and have learned a lot... maybe I could be of assistance.

[langleylad]

If you'd like me to come over one day and help you go thru the wiring, I'd be happy to. I've recently redone my battery/fuel pump wiring, but I've also been refining my electrical/wiring process and mentality over the last several years and have learned a lot... maybe I could be of assistance.

Thanks for the offer, since Holley EFI is pretty much plug and play there’s only a 10 or so single wires that need to be dealt with. I just need to be sure that I have them going to where they need to. I can handle that but thanks again anyhow.

[frojoe]

Thanks for the offer, since Holley EFI is pretty much plug and play there’s only a 10 or so single wires that need to be dealt with. I just need to be sure that I have them going to where they need to. I can handle that but thanks again anyhow.

Sounds good, no worries and happy to be a local resource to help out if needed. Can't wait to see this thing running/rolling!

[langleylad]

Scratching my head here , should any voltage at all be getting through to the ignition circuit when the key is in the off position?. It seems I’m getting 8.5v.

[andrewb70]

No. That voltage sounds like what would come out with the stock coil resistance wire. I'd say your ignition switch is bad.

Andrew

[langleylad]

No. That voltage sounds like what would come out with the stock coil resistance wire. I'd say your ignition switch is bad.

Andrew

Thanks ! Amazon is delivering one tomorrow . I ordered one on Saturday , too much goofy s**t going on here.

[andrewb70]

Let's hope that does the trick!

[langleylad]

Let's hope that does the trick!

Yes Sir ! , I'll keep you posted ! .... ouch ! lol

Mike

[Krazed]

Any luck with this?

Fantastic build by the way, one of my favorites especially considering it's entirely garage built and still has all the fancy electronics!

[andrewb70]

Mike will get it sorted!

Andrew

[langleylad]

Any luck with this?

Fantastic build by the way, one of my favorites especially considering it's entirely garage built and still has all the fancy electronics!

Yes , got it figured out today. Turned out that it wasn't the ignition switch , so I have a spare sitting on the shelf. The Dominator has a wire (red/white) from the main harness that needs to be connected to a switched 12v source and there is also a wire (red) from the electronic transmission harness that also needs to be connected to a switched 12v source. These two sources have to be separate from each other. If they're on the same circuit , they will back feed into each other and the engine won't shut off if started and other weird things happen that will have you scratching your head. Believe me. I thought I had them on separate circuits but apparently not. I connected the red/white to a ignition port on the fuse box and the red wire to circuit for electric fans. I'm using an American Autowire harness. My electric fans will be controlled by the Dominator. Which leads me to tonight's efforts in the shop. Aided by Andrew's YouTube video https://www.youtube.com/watch?v=7C-Y0VsD6pY&t=275s .
I was trying to program the cooling fans but was struggling a little, I'm tired and I'll try again tomorrow. But it did feel good to be able to start it and stop it with the key lol!. Here's a pro tip , instead of disconnecting the power lead a the pump and lighting the trunk on fire. Just pull the fuse to the pump . lol .

Thanks for the kind words

Mike

[langleylad]

Mike will get it sorted!

Andrew

Thanks for the vote of confidence and for your help Andrew , much appreciated.

Mike