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Ignition switch and electrical flow question


zdude1967

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I am trying to determine if my ignition switch is bad. Some history on the issue: I have a starter button which connects directly to the starter. The starter will engage without the key by pressing the button. It will however not start if the ignition switch is not in the on position. I believe this is because there is no electrical flow or spark. Currently I have no electric flow when the key is in the arse or ON position, ie no wipers, blower etc. Also no spark. I used a multi meter and tested all 5 wire connectors that hook to the ignition switch, I have power in one only it is the white /red wire. Is this correct or am I susposed to have power in all 5 wires. I have attached a photo for clarity. Could someone please help I am at the end of my patience.

post-16936-14150814929384_thumb.jpg

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First, always include year and model.

second start by bench testing the switch before you go for the wiring harness,this is very important when trying to figure out what the PO has done to (you and) the car. Test continuity thru the switch in it's various positions to ensure the switch is good and then you can eliminate it as the problem. Once you have reliable switching check your circuts one at a time using first the FSM and second by tracing PO added circuts.

My GUESS is that the switch is bad, or the PO wouldn't have gone thru the trouble of butchering the wiring in the first place.

BTW, that picture shows almost nothing, and nothing of use to help us help you.

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I believe the red/white wire is from the fusible link. This establishes that your fusible link is good and that you're getting power to the switch.

Try testing for continuity between the switch terminals on the disconnected switch when you turn the key. That's the most direct approach to determining whether your switch is good. Again, red/white is the power supply to the switch, so test for continuity between that terminal and the others.

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1974 260z late model November production. Well I bought the new lock and switch and just received it. My lock was shot as the key could be removed in any position so I felt either way it would be a good idea to replace it. It has however not solved the problem as no power. I hooked a wire to the battery positive and connected it to the coil positive. The car has power this way and starts. It does run like crap but it starts. Since the switch is good wher do I go from here...my understanding is that the power goes from the ignition to the ignition transistor then to the coil and the dist. Is this correct.

Thanks

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Have you checked your fusible links? Specifically, the Ign link and its circuit? When you connect power to your coil positive you might be feeding power to the ignition circuit, bypassing the fusible link.

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Zed head, I believe this car has two fusable links. they seem to be OK. Here is another issue discovered yesterday. Steve perhaps you have some insight into this...The car is running poorly, I started it with the battery wired to the coil trick. I hooked a timing light and with with the dist lined with the timing mark at the adjustment nut the crank pulley timing mark is not even close to the timing degree tab. If I remove the dist nut and crank it as far as it will go towards the drivers side the timing mark gets closer to the crank pulley and timing tab but still a good 1/2 inch away from the entire degree measurement tab. Whats the deal. It also seems to idle way too high. All the carb idle throttle speed screws, balance screws etc are backed out to the point they are not even touching anything but the rpms are 1200 to 1300. It does lower when the dist adjustment screw is removed and the dist turned all the way towards the drivers side as far as it will go. At this point it also backfires through the carbs. My poor sick Z and my less then needed Mr Goodwrench skills are not seeing eye to eye. Any thoughts

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Dude, check the breaker plate in your dizzy to see if it still rotates freely with vacuum applied to the vacuum advance. The vacuum advance mechanisms in Z dizzies aren't very well designed and often/frequently/usually stick. For $100 you can buy a rebuilt dizzy from your local auto parts store (e.g. AutoZone), but supposedly supplies are getting a bit scarce.

Backfiring through the carbs strongly suggests a fuel/air mix that's too lean. I bet your engine vacuum is pretty low too.

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Your damper may have spun also. If it has you will have a hard time timing it correctly. I would verify TDC and the timing marks as a first step. As to your wiring problems you are going to have to use the schematic to trace the wiring and fine out how the PO modified it.

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