Battery has full charge but!
 

Need a little help guys .I have a poor man's gto with the 400.1967 battery is full charged .when I turn the key nothing and with key on or off no lights.horn does work.got the car up 18"used my creeper and jumped the starter ,it engages just like you were turning the key tried it twice for a few seconds.fusr box under dash looks good I do have a started relay on the fender.what do you guys think if it's the ignition switch does the dash have to come out 71 years old now .that would be tuff for me.your knowledge is second to none!what do you think?

Check you fuse panel for power with the key on. does the dome light work when you open the door?

Check/tighten the underhood 3/8 bolt that clamps the fuseblock together.

Column Lock
 

Not sure if your car has this. My 1969 Firebird has the linkage that actuates a collar w/switch on the steering column that will interfere with starting engine.

No it doesn't just wondering if I should start it by jumping starter and just let it run...see what happens

No no lights battery fully charged jumping works fine alternator maybe?

Did this issue come up after you made any changes?

Neutral start safety switch gone bad? Not sure how that affects any lights tho. When you say "no lights" is it dome light and/or headlights?

It's a rag tip but no interior or headlites

I went into the garage and it started right up for one second and then nothing ever since.no changes except black widow mufflers

Ok tomorrow

I thought maybe neutral safety but no lights has got me

I erased this idea, but here it is (again);
Clean Pos+ Battery post & clamp of a dark gray corrosion as it acts as a 1-way diode.

As asked before any recent work done? Check all grounds,if you can get it to crank by jumping starter under car( putting 12v to "S" terminal) you have to ck why you are not getting power to the starter solenoid from ign switch. BTW stick or auto? Forget alternator. You say no headlights? Also ck bulkhead connector on firewall "S" wire would be coming from Ign switch down to starter via this connector. Headlights would go though here also.

I'm thinking a fusible link gone bad, or maybe somewhere between the fusible link and where the battery splices in. On a Tempest, it looks like the electrical tie in point for +12v power is at the starter battery terminal. Different platforms tie in this +12v different places. 1st gens tie in everything at the born relay. 2nd gens tied in at the starter.

Disconnect the battery first
Then loosen/remove the bolt in the fuse box bulkhead connector - it is under hood - on the firewall.
It pulls out like a receptacle from a wall plug.

My van lost power to a lot of stuff once , and that was the problem.
Bad corrosion on 2 of the lower pin connector terminals.
One of them - the wire had broken off from it's pin terminal connection.
It hit all at once - no warning signs.
Don't know how it kept working while it did in such bad condition.

Had to bypass those 2 pin terminals , with spliced wires going through where those pins were.
Instead of finding another underhood harness for a 1989 Dodge van.
The broken one had to be done , the other one was preventive maintenance.

Usually there is a rubber boot that covers the exterior of the bulkhead connector.
Roll it back to inspect the actual wire-to-terminal connections.
Those boots will hold the water in the bottom if any gets in from the top.

If no lights also, the main feed wire thru the firewall is the culprit. Therefore you are getting no power into the cabin as evidenced by no lights. The light circuit is not fused separately. The fusible link in the harness could be bad.

George

I think some on here may be missing the fact he is running a fender mounted relay (guessing a ford type solenoid?)? If so, it is not a stock configuration and a few ways to wire and/or screw this up.

If you can 'jump' the starter from underneath the car, the main/big cable to starter must have power to it when you do this. This would suggest the fender solenoid is being activated - are you jumping connections there as well to send power to starter or is someone hitting the key while you are jumping the terminals underneath?

How is the S terminal down at the starter normally getting power? Jumper wire from main power cable at starter? Separate wire from fender solenoid? Wire from stock harness? I would start my troubleshooting there.

S pole getting power from fender relay,jumping starter with key on
 

s pole getting power from fender relay.jumping car with key on from u derneath.the key does nothing ,no lites in or our ignition switch maybe

It would actually start the car by jumping underneath or would the starter just keep engaging the fly wheel i am jumping with 2 gauge wire from starter main to s pole lot of juice