Starter automatically engages when hooking up new battery

[Odoyle]

Trying to figure out what I have done wrong, when I connect a new battery, the starter is engaging the flywheel without the key in the run position! The car is a 77, any explanations are welcomed. Thank you in advance.

[spider2081]

There are to 5/16 studs on the starter solenoid. The one closest to the engine should only have the wire going directly into the starter motor. The other stud should have the battery positive wire on it, a brown #10 that goes to the fuse panel and a black #10 wire that connects to the alternators output post. I would check and make sure the starter solenoid is wired correctly and the terminals are not shorted together.

[Odoyle]

Ok starter solenoid is wired correctly, I was suspicious about the ignition switch and pulled it out and realized I forgot to put the metal cylinder spring inside the middle of the switch, put that back in and everything seemed to be working ok for a few minutes, cigarette lighter, interior light, hazards were all working until the light blue wire (doubled up with pink) on the fuse A unprotected side started to burn out and smoke. I disconnected the battery immediately afterwards. The light blue wire goes to C25 where it is doubled with a pink which goes to 18/4. Both the pink wire at C25 and fuse a both look completely unaffected. Light blue wire after C25 goes to tac also is wired correctly and looks fine. Any thoughts?

[spider2081]

Do you have a wire diagram for your car?? Looking at a 1984 diagram I am having trouble locating/following your circuit description. I believe C25 is the ignition switch 6 cavity connector. The 83-85 Spiders are wired slightly different than th e80-82. I can't locate 18/4, is this a contact on the ignition switch? If it is could it be 15/54?
The center contact on the later model Sepia ignition switches is primarily light circuits It is usually labeled "INT" and has 2 terminals with only one being used. Its should have power with the ignition switch in either the "start" or "Run" positions

Hope this helps

[Odoyle]

spider2081, sorry for confusion, this is all in my 1977 spider, not the 83.

[spider2081]

Now that makes sense I was looking in all the wrong places. My wife tells me this all the time.

Anyway the wire diagram I have for a 77 agrees close to yur findings. It shows the wire from fuse A to C25 being light blue with a black trace which is close enough. For just the light blue wire to be affected is pretty strange. Any chance its smaller diameter than the pink wire?? that could let its insulation melt while the other wires were not affected.

Does your idle stop solenoid make a clicking sound if you momentarily connect and disconnect the wire to it with the key on??
I would take an inline fuse holder and put a 5 or 10 amp fuse in it. Remove the terminal with the pink and the light blue wire from the top of fuse one and connect the inline fuse holder to fuse 1 and the removed terminal. That way your wires are now protected with the new inline fuse. Power the car and see what happens to the fuse.

My suspicions would lean toward a shorted idle cut off valve.

Hope this is some help