#1  
Old 03-29-2020, 05:00 PM
jpg69bird jpg69bird is offline
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Default No voltage anywhere

Go to start my '76 Trans Am, and when I turn the key, absolutely nothing happens. No power to any of the accessories, lights, dash, etc. Obviously, nothing happening at the starter.

Checked basic connections under the hood. Wire to the alternator from the hot was nice and tight, ground to the block was fine. Hot to the starter was connected. It's a 4 speed, and the lock out mechanism seems to work. I can't pull out the key, unless I am in reverse. Connected jumper cables from my other car. Nothing.

Guessing that it might be the ignition switch, I looked for videos on replacing the switch, but I only find how to replace the cylinder.

Being a parts replacer and not a mechanic, this might sound like a stupid question, but where is the electrical switch, and how can I replace it?

Or, could it be some other wire/relay that might have come loose?

  #2  
Old 03-29-2020, 05:06 PM
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Sirrotica Sirrotica is offline
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If the headlights don't work it's not the ignition switch.

You need a VOM, or at a minimum a test light to find where the current stops after it leaves the battery.

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  #3  
Old 03-29-2020, 05:11 PM
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johnta1 johnta1 is offline
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Have a voltmeter?

If factory wiring still, the main power comes from the big red wire that connects from the starter lug with the battery cable to the alternator.
There should be 12 volts there.

Make sure the battery cables on the battery are clean and tight.
Check that the connection at the starter where the battery cable connects is tight.

You can run a jumper wire from battery + to the post on alternator where the big red wire connects.
There should be power to the car then if battery isn't dead.

Notice if there are any strange things going on when doing this.


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  #4  
Old 03-29-2020, 05:15 PM
jpg69bird jpg69bird is offline
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No headlights. I have a voltmeter. The terminals are tight on the battery, but didn't matter once I connected the jumper cables.

I'll jump back under tomorrow (if it stop raining) and try to find the break.

Sirrotica, thanks for letting me know its not the switch.

  #5  
Old 03-29-2020, 07:47 PM
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LATECH LATECH is offline
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No Lights/headlights either?

Sounds like a fusible link, or the connector on the bulkhead.

Look down on the starter for the fusible link. Might be burnt.
Bulkhead connectors can be an issue.All the power to the switches/lights etc has to go through there.
The alternator big wire most likely has its own fusible link/ connection at the starter.So it could be hot, while the rest of the car has no power.

You could turn on the ignition and the lights, while the car is dead. Then carefully go around the harness and move the wiring around to see where , if at all, things come to life. We call this a wiggle test.If there is a loose connection somewhere and you wiggle the harness close by, it may power up,or flicker, giving an indication of the location of the problem.

Also a fusible link may be burnt.It is a wire tha burns in half,like a fuse when a short is present. When you see it, it may look OK, as the insulation doesnt always burn off, but if you pull on it and it stretches , the wire iside is burned in half. It will be on the big lug on the starter.


Last edited by LATECH; 03-29-2020 at 07:55 PM.
  #6  
Old 03-29-2020, 08:58 PM
MUSLCAH MUSLCAH is offline
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Had that happen....I cleaned the battery posts again and cleaned the spring cables again...and all was well again....

  #7  
Old 03-31-2020, 03:15 PM
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killakev killakev is offline
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Check the 30 Amp fuse that usually sits in the wire bundle of driver side intake manifold

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