ignition woe

[buckspet]

My 1980 carb'd spider came with a bastardized generic ignition switch, it was so home made the PO actually welded a large washer onto the steering column to accommodate the switch!!! So after chiseling off that wacky washer I installed a original from a 81 FI spider. All the wires fittings matched up and it looked original. Unfortunately when I turned the switch on it would start when turned completely to the right, but when let go to the running position it shuts off! So with the key in the driving position the system isn't getting power. Since both the original harness's match up, I believe the PO must have changed the wiring configuration, electric. Issues are my worst automotive skills, and I'm 6'4" 280 lbs. I literally have a terrible time under the dash. I need all the knowledge I can get before, shoe honing myself into the claustrophobic under dash area. The starter turns normally, but as soon as I release the key no energy. Please help,to lead me Virtually through the procedure

[spider2081]

Personally I think its a good idea to post where you live in case some with lives near you that might assist you.

The ignition switch in the Fiats Spiders get a lot of negative comments in chat rooms. I think the original switches were pretty good and sometimes get changed when there are other real causes of the problem.

Do you have a trouble light or volt meter to check the circuits with?? If so I will attempt to make some meaningful checks that do not require you to go under the dash.
Are the wires secure at the alternator output terminal?
Do you have parking lights lit with the headlight switch in the middle position? ( up should be off) and the ignition switch off.
Do you have head lights with the headlight switch in the down position and the ignition switch in the "run" position ? The headlights should turn off when the ignition switch is off.
With the ignition switch in the "run" position is there power on the fuse closest to the steering column?

With the ignition switch in the "run" position is there power on the pink wire on the ignition coil?

Let us know what you find

[baltobernie]

All the wires fittings matched up and it looked original.

Do the terminal numbers on the back of the ignition switch match the wiring diagram? You can find the diagram corresponding to your M/Y by searching this forum. Yes, it is possible that a PO replaced the harness on your car, but that is a Big Job. So before leaning in this direction, eliminate the easier items first. You know that there are "early" and "late" ignition switches? They look the same from the front, and have identical dimensions. Here's the business end of the "early" switch:

[80spiddy]

It reminds me of an issue that arises with older points style ignition as on my 55 Chevy. On this there are two terminals on ignition switch, ignition 1 and ignition 2. When switch is turned to start, 12 volts go to coil and distributer to start. Once started and ignition switch released back to run, the electrical system doesn't need the full voltage anymore. But, if switching over to electronic ignition, these two wires to ignition switch MUST be jumpered together. Otherwise, when you release the start to run, the engine will die because it doesn't get the continuous voltage needed.

[wizard124]

Check the switch itself. Could be bad internal contacts