Engine vibrating 3K+ rpm.

ttocs

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that is the +12v switched ignition feed into the switch. If it were to draw too much current it would just pop a fuse.
 

Chenn2389

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I replaced the switch and the plug. The good thing is my fog lights and charging ports work again. The bad news is the wiring is bad further down stream than the plug. The parking/running lights and all of the dash lights and door chime are staying on with the ignition off and the key out. I think I am gonna replace the ignition cylinder, switch, and pigtail. How nice of my wire harness to play these fun games. Can a shorting ignition switch cause intermittent misfiring? I’m not getting any check engine lights, and when I pull the codes I just get the pass code.
 

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Those issues wouldn’t be caused by the ignition switch or cylinder. How do you know the wiring is bad? If by staying on you mean with the switch in the off position, that’s the headlight switch.

As for your misfire, it has nothing to do with the ignition switch or headlight switch. Did you do a compression test? Did you swap out the distributor with a stock one to rule that out?


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Those issues wouldn’t be caused by the ignition switch or cylinder. How do you know the wiring is bad? If by staying on you mean with the switch in the off position, that’s the headlight switch.

As for your misfire, it has nothing to do with the ignition switch or headlight switch. Did you do a compression test? Did you swap out the distributor with a stock one to rule that out?


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I triple checked the pigtail wiring for the headlight switch and tried two different switches. It’s color coded and I used the old pigtail just to be sure I connected it the same. All the interior lights and running lights are staying on with the ignition off and no key in. This is why I think when my headlight switch burned up so did the ignition switch. There has to be a short on the other end of the headlight pigtail as well.
 

ttocs

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it sounds like something was not right on the wiring for the new harness since the lights starting staying on after. Replacing any other parts will probably not fix it. I would go and triple check your wiring before I throw any more parts at it.
 

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it sounds like something was not right on the wiring for the new harness since the lights starting staying on after. Replacing any other parts will probably not fix it. I would go and triple check your wiring before I throw any more parts at it.
The pigtail for the switch is wired properly.
 

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The harness was burned up. I replaced it, triple checked the wiring against the original pigtail (the wires are color coded it’s impossible to get it wrong). I tested it using two different switches. It’s not the pigtail or the switch. I am assuming what ever caused that wire to get hot in the first place down stream from the pigtail also burned up on the other end and is shorting the circuit. I haven’t taken the lower dash and column apart to find it yet.
 

07GtS197

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The ignition switch has nothing to do with the lights. If you disconnect the switch do the lights go out? I’m still thinking that issue is the switch itself.


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ttocs

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The harness was burned up. I replaced it, triple checked the wiring against the original pigtail (the wires are color coded it’s impossible to get it wrong). I tested it using two different switches. It’s not the pigtail or the switch. I am assuming what ever caused that wire to get hot in the first place down stream from the pigtail also burned up on the other end and is shorting the circuit. I haven’t taken the lower dash and column apart to find it yet.

The stock switch harness has been known to melt for years now just because of the heat that builds up in it. I don't think I have ever heard of anything specifically that causes it to melt as far as shorting wires front or rear, just that its a known weak point.

"(the wires are color coded it’s impossible to get it wrong)" - I have been doing automotive wiring for almost 30 years and I have yet to know of a system that has been made that makes it impossible to be wrong or for someone wire it wrong. I have seen harnesses that have the pins in incorrect places or wire colors that almost match but if you look closely maybe it a dark blue wire, not black and as much as I pride myself on testing all my connections before I connect to them, I have screwed them up. If it were me I would be looking up that specific wire harness and again triple checking that the wires are going to the correct part on the harness or that there maybe isn't a connection that has shorted out once you put it all back together. Shit happens.

But as he said this will not cause the car to run bad. I am not sure if your confusing the ignition system(coil/dist/ect) with the 12v switched ignition wire that powers the system. The switched/ignition wire powers the system but if another system is drawing too much current from that wire it would just pop a fuse.
 

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The plug is wired correctly. I even cut out the new pigtail and soldered it a second time because my initial thought was I had to have done something wrong. like I said I triple checked the pig tail wiring it is not wrong. I even used the wires in the old burned pigtail as a guide on the second time to make sure the color coded wires are correct, they are. The pig tail is not the issue. Perhaps both switches I tried are also bad right out of the box, but unlikely.
 

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The ignition switch has nothing to do with the lights. If you disconnect the switch do the lights go out? I’m still thinking that issue is the switch itself.


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I am sure the pigtail is wired correctly, its been triple checked and soldered two different times to ensure its correct. I tried two different switches both are doing the same thing. I am going to chase the wires down the column and under the dash to see if there is a short somewhere else further down. If there are no other shorts, then I will try a third plug. Wouldn't a bad ignition switch be sending 12v to the headlight switch when the ignition is off?
 

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I believe my misfires have to be mechanical, or leaking head/intake gasket at this point. I replaced the coil, cap, rotor, plugs, wires. I checked and reset the fuel pressure. I put noid light on the injector harness at all the injectors. The injectors were flow and bench tested before I installed them. I verified the PIP is working and advancing the timing on the distributor. I took the TPI in and it bench tested good at AutoZone. I pulled the KOEO codes and its not throwing any codes. I pulled my EEC and checked the board for any burnt up spots, recleaned the pins for the connections on my moats chip. I checked the TPS voltage and insured its good. Only things I haven't tested are the O2 sensors, which are brand new motorcraft, and the MAF. I unplugged the MAF at idle and the car died. I am not sure if that's normal.

I couldn't get the car to run the KOER test or cylinder balance test.

I need to get my electrical issues taken care of, then I will take the car into the builder to do compression test and leak down test, and check the lash on the valve train. They are already going to be doing a rear main seal since it is leaking a lot.
 

ttocs

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power for the light circuit is on a constant power if its working right that is why you can turn the lights on with the key off. The switched power input on that switch is more than likely for the windshield wipers/turn signals that do not work with the key off.

Since we are sure it can't be the switch or harness then you need to look downstream in the wiring. Unfortunately this sucks as you literally need to trace the wiring from the switch to the lights and check every inch that you can. I am not sure where to tell you to look honestly except any places that you have previously been doing work and might have pinched or shorted something otherwise if this short theory of yours is true it could be at any of the corners of the car or anywhere in between.
 

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So with the headlight switch and the ignition switch unplugged entirely the instrument lights, dash lights, and parking lights are illuminated it makes no sense at all.
 

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The pig tail is wired correctly, I checked every fuse in the car and replaced them all. The fog lamp fuse and instrument panel fuses were blown. I replaced them at the same time I rewired the new pigtail. I’m lost. The circuit is shorted somewhere with a constant power wire.
 

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From my Haynes manual. The brown wire is for the exterior lights, the LT blue/ red wire is the interior lights. The tan/white and light green/yellow are the constant power wires. With fuse 13 removed the interior lights stay on. The tan/white, brown, and lt blue/red wires have to be shorting together somewhere I just can’t find it.image.jpg

Is there a way to move this into a new thread for just the lights. This has nothing to do with my misfires.
 

ttocs

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well if the lights stay on all the time with the switch disconnected then its either the harness(I know I know its not the harness) or as you suspect something downstream that is shorted. The brown wire is for the exterior parking lights and that circuit might also feed the dash lights

Did you remove the gauges? If so then take them back out, disconnect the harness to it and then look inside the connections and make sure the copper traces have not lifted and are shorting.
 

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well if the lights stay on all the time with the switch disconnected then its either the harness(I know I know its not the harness) or as you suspect something downstream that is shorted. The brown wire is for the exterior parking lights and that circuit might also feed the dash lights

Did you remove the gauges? If so then take them back out, disconnect the harness to it and then look inside the connections and make sure the copper traces have not lifted and are shorting.
Ya the instrument cluster is out, ignition switch and headlight switch are out, I also pulled fuses 5, 8, 13. So there should be no power to interior lights or parking lights at all, and am still getting power. Only place I can think of is the trunk lamp, third brake light, license plate light all meeting in the trunk only other place where I see the green/yellow and brown wires meeting in close proximity. The hot wire green/yellow fuse 8 and lt blue/red fuse 13 basically touch at the fuse box but I see no signs of damage there.
 

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I pulled my upper intake manifold. I checked the lower intake manifold bolt torques and they were not to spec or some of them backed out. I looked in the runners and there is noticeable oil entering between the heads/intake. There is coolant as well as far as I can see at the #1. Valves are noticeably wet with oil and discolored. I can’t take a decent picture. I’m guessing I don’t even have a rms leak. I just a significant lower intake manifold leak. Probably both.

Anyways the engine builder assembled the engine including the lower intake manifold. He had to fly cut it a bit on the mill to get it to align perfectly. Mismatched edelbrock heads with trick flow intake. At this point I should probably pull it and have him tear it down and go through it. Too hot to drive it in AZ so idc if I lose 3 more months at this point.
 

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