Ignition Switch going bad?

[michaelj]

Sometimes when i go to start my car, I turn the key and the starter does not engage. I hear the fuel pump, but thats it. Then i shut it off, and turn it back to start and it cranks. SOmetimes i need to do this 2-3 times. The starter is fairly new with less than a thousand miles on it. I was going to replace the ignition switch but if its the starter solenoid..i just hate to waste the money. Any tests for this? If it would just break it would be easy to figure. But its intermittent. Thanks much. Mike

1976 124

[RRoller123]

Check the connector C31 immediately in back of the ignition switch, and the ignition switch connections themselves. Those 2 spots have been common causes of this symptom.

[obdulio39]

I know what your problem is. I had the very same thing. #1 buy a new switch #2 disassemble the switch completely and you'll see the problem. the actual switch can be taken apart and the points cleaned: with time the contacts burn from sparking and you must sand them clean and bend them to compensate for the loss of metal. don't spend 200plus on a new switch. it worked for me like a charm. also decided to add a push start relay that way you don't use the part of the switch that sends electricity to the starter just put the switch to II and use the push start button.

[ga.spyder]

I just recently had a similar issue.Take a look at some of the pictures in the thread.
http://www.fiatspider.com/f08/viewtopic.php?f=5&t=29071

[vandor]

> The starter is fairly new

If it's a remanufactured unit then 'fairly new' does not mean much. They were not that great when the cars were new and now 30-40 years later after they have been rebuild 5-10 times they are far from reliable.

[PininF]

Going through the same problem , at first I thought it to be the alternator then the starter motor and then maybe the battery…
After reading this thread I'm sure it's the ignition switch.

Thought to share some info I found and good to bookmark.
http://www.dcfiats.org/tech/Fuses_Relays-B.pdf

[blazingspider]

You can test the ignition switch with an ohm meter.

The terminal numbers are marked on the backside of the switch next to each spade. #30 (brown wire) is your power in and #50 (red wire) goes to the starter. Remove all of the wires from the switch remembering where each went. Clip your ohm meter leads on to #30 and #50. Turn the key all the way to the crank position, and you should see continuity at the meter. You can jiggle the spade terminals on the back of the switch to see if you lose continuity intermittently.

If that all checks take out look at the female spade terminals crimped on the wires to make sure that they fit snuggly over the spades on the switch. Also take a look at the white connector block that the wires terminate to. I've seen them burned and melted from the amperage going through those connections.

At some point in time Fiat soldered those wires to the back of the ignition switch. If that's your case you can perform the same test above by following the wires to the connector blocks, pulling them apart and testing at the spades that are attached to the brown wire and red wire inside the connector.

A couple of final notes. There are 2 #30s but the brown wire will be on only one of them. Both terminals are just one piece of metal on the inside. Also don't get confused with terminal #30 and #30/1. They are not the same. #30/1 has a black wire connected to it.

Good luck

[spider2081]

A good electrical connection has no resistance within the contact and therefor no voltage is developed across the contact.

There is no need to disconnect anything from the ignition switch to test it.

First visually inspect C31 the connector about 6 inches behind the ignition switch for discolored, burnt and loose contacts. I like to use a male test contact to check all the female sockets. They can be purchased at any electrical supply place even your local Home Depot sells them.

To check the ignition switch internal contacts in the "start" position it is best to use a voltage test. Connect one volt meter lead to terminal 30 and the other to terminal 50. Rotate the switch to the "Start" position. Ideally the meter should read 0 (zero) volts. The greater the voltage reading the more resistance exists between the internal contacts of the ignition switch. This test is most meaningful if the starter only click's (duplicating the symptom). Intermittent problems are best trouble shot when the symptom can be duplicated. It might take numerous tries duplicate the symptom while testing.

How this test works:
If the starter clicks and the voltage reading across the switch is zero the switch is not likely your problem.
If the starter clicks and the voltage across the switch is greater than 1 volt the switch is at least part of the problem.

With our old cars there can always be more than one thing contributing to a problem. ex poor ignition switch and weak starter.