Ignition Switch woes

[phillyfiat]

I've read through a few different posts here on the issue, but wanted to confirm that what is happening is what I think it is. I have a 1979 spider that recently started having a no start issue. When I turn the key it will crank, but I get no lights on the dash and the fuel pump does not start. I have power else where (door chime, lights, radio, etc.), but none to the dash/fuel pump.

It seems the likely cause is the ignition switch, but before I replace I wanted to see if I'm missing something else. Thoughts?

[stuartrubin]

This advice may sound ridiculous, but it helped me. When you turn the key, jiggle the wires coming from the switch. If you get some momentary activity (lights, etc.), then you may have a problem with the switch. (This is how I figured out that my switch was broken.)

[bobplyler]

The 79 came with a mechanical fuel pump. Have you checked that the carb is getting fuel.

[phillyfiat]

My 79 actually has an electric fuel pump mounted in the trunk close to the tank. You can usually hear it run when the key is set to on.

[phillyfiat]

This advice may sound ridiculous, but it helped me. When you turn the key, jiggle the wires coming from the switch. If you get some momentary activity (lights, etc.), then you may have a problem with the switch. (This is how I figured out that my switch was broken.)

Stuart -- Gave this a shot and at this point I've got nothing. It has gotten progressively worse which is why I'm thinking ignition switch -- used to be I could flip the key from off to run a few times and I'd get gauge lights and a running pump. At most I would give it a quick crank and then it would fire up. Now I've got nothing.

Going to move forward with an ignition switch replacement and move from there.

[spider2081]

Going to move forward with an ignition switch replacement and move from there.

Replacing parts without real troubleshooting can make for expensive repairs.

[phillyfiat]

Replacing parts without real troubleshooting can make for expensive repairs.

Any thoughts on what might be the root issue here? Or troubleshooting steps I should take before popping out the old switch?

[spider2081]

Any thoughts on what might be the root issue here? Or troubleshooting steps I should take before popping out the old switch?

I would measure voltage on the cars side of the ignition switch connector. Both the brown and the black wire bring battery power to the ignition switch.
The blue wire and the pink wire are switched power out of the switch in both "start and run" positions of the key
The red wire is power out of the switch in the "start" position of the ignition key
The test can be made with either a volt meter or a 12 volt test light.
The ignition switch connector has 6 cavities but only 5 wires.

[TX82FIAT]

Just for kicks, try disconnecting the negative battery cable for a few seconds and then reconnect and try to start.

[phillyfiat]

Spider2081 -- I'll give this a shot -- thanks. Need to grab a new multimeter since mine seems to have gone missing. I'll update once I have an idea of what's going on with the wiring.
TX82 -- I tried this early on thinking the same thing (worth a short, right?) to no avail. Appreciate the idea though.

[phillyfiat]

Update:

Brown and black: constant 12v
Red: 9-10v in start
Pink: nothing in start or run
Blue: nothing in start or run

Thoughts at this point?

[spider2081]

The black wire gets switched to the pink wire by 1 set of contacts inside the ignition switch.
The brown wire gets switched to the blue wire with a different set of contacts inside the ignition switch.
the brown wire gets switched to the red wire through a 3rd set of contacts in the "start position of the ignition switch.
Your test results indicate 2 of the three sets of contacts inside the ignition switch are bad or that the ignition switches 6 pin connector has a problem. By chance did you measure the voltage on both the cars and the ignition switches connectors?
Often when the ignition switch contacts are bad there is still a measurable voltage on the pink and the blue wires. Just not the full battery voltage. Measuring zero volts is strange especially on 2 of the wires.
It might be worth while to perform the test one more time.

[phillyfiat]

The black wire gets switched to the pink wire by 1 set of contacts inside the ignition switch.
The brown wire gets switched to the blue wire with a different set of contacts inside the ignition switch.
the brown wire gets switched to the red wire through a 3rd set of contacts in the "start position of the ignition switch.
Your test results indicate 2 of the three sets of contacts inside the ignition switch are bad or that the ignition switches 6 pin connector has a problem. By chance did you measure the voltage on both the cars and the ignition switches connectors?
Often when the ignition switch contacts are bad there is still a measurable voltage on the pink and the blue wires. Just not the full battery voltage. Measuring zero volts is strange especially on 2 of the wires.
It might be worth while to perform the test one more time.

I did measure on both the car and ignition switch connectors and I should correct myself -- I got less than a volt on each for the blue and the pink.

Though looking back, I realize I forgot to add that it seems the PO cut the blue (looks like it got a bit hot...) and added a jumper to the pink. Photo links below.

https://flic.kr/p/2mps34k
https://flic.kr/p/2mpqW1V

[spider2081]

it seems the PO cut the blue (looks like it got a bit hot...) and added a jumper to the pink. Photo links below.

That is important information. What has been done eliminates one set of contacts inside the ignition switch. The entire cars switched electrical load is not being switched be a single set of contacts instead of 2 and being fed be a single black wire instead of 2 . Original configuration was to be fed by the black and the brown wires. Now the brown wire feed is only being used to engage the starter.
The single set of contacts being used may have failed because they are working too hard. They were not designed to carry the entire load of the car, So yes the ignition switch may need to be serviced.
Additionally the burnt 6 cavity should to be replaced and the cars wiring made as original as possible.
For situations like yours I suggest getting a new 6 cavity connector prefabricated with leads about 6" long made with $ 12 wire and the correct colors. This new connector is then butt spliced color for color to the original cars wires.
This would eliminate the green jumper and have the ignition switch use both set of contacts instead of just 1 as it presently is wired.
The burnt connector is most likely cause be an excessive load on he blue wire. Either lighting or audio load had been added improperly. Or there may have been a short on a switched power wire before the fuse panel.

I sent you a private message on this site.

[phillyfiat]

Thanks Spider -- replied to your pm and will keep you updated.