Ignition switch bypass?

[70spider]

Is there a way I can bypass the ignition switch to start the car to see if the no start problem is the ignition switch. If it is a bad ignition switch, crazy thought, can I permanently bypass it and use a push button start? Cheers .

[4uall]

I want to say "yes"

https://www.youtube.com/watch?v=be5TDIpEjN8

http://www.fiatspider.com/f08/viewtopic.php?f=7&t=24725

[azruss]

yes. there is a small wire going to the side or front of the starter. It plugs into a male 1/4" spade connector. Make yourself a long jumper with #12 to #18 wire and connect a female spade connector to it. plug this jumper into the starter in place of the small wire. turn the key to on and touch the other end of the jumper to 12v, preferably the battery +. make sure you are out of gear. If the starter jumps to life then the problem is with the ignition switch or one of the electrical connection in the starter circuit. Before going to the trouble of adding a start button. clean up all the connectors in the starter circuit.

[70spider]

Thanks for the replies. I figure this might work http://www.banggood.com/Ignition-Engine ... aQodCQMA8Q
Any thoughts?

[4uall]

Now you have me wanting one LMFAO

http://www.ebay.com/itm/Auto-Car-Univer ... 0872491659

[azruss]

Tread lightly here. You know how easy you can offend the Fiat gods with creative wiring. Remember someone else will most likely have to deal with your modification after you give the car up. Carma's a bitch.

[baltobernie]

If your OE switch is worn enough to cause problems in the Start position, it is probably worse in Run. After all, the starter solenoid doesn't take much current to trip, and certainly not long in duration. Bad contacts in the Run position will cause the car to experience intermittent engine failure, and it never seems to happen at a convenient time

Repair or replace the switch.

Or ... learn the "two-step boogaloo", where you immediately depress the clutch, observe if the tach has also died (telltale), turn the ignition OFF (but not Lock, where you will crash), wiggle the key in the cylinder, turn key to Run, select next lower gear, slowly release clutch ... but not too much or Mommy will rear-end you with her SUV, turn on hazard otherwise and look for nearest landing strip, etc.

[spider2081]

do you want to by pass the switch to test it or because you think the start position is bad?

I tried to bench test the pull in current for my 81 Spider starter solenoid and found it pegged the 20 amp meter on my bench power supply. Here is an interesting article on Starter solenoid operation and expected currents. I don't know if most Starter solenoids are of similar design but I would guess they are.

http://www.aeroelectric.com/articles/strtctr.pdf

Some auto and motorcycle manufacturers install a starter relay that has 30-40 amp contact current rating to protect the ignition switch between the ignition switch and the starter solenoid. A momentary push button switch capable of reliably replacing the start position in the original ignition switch would have to be physically fairly large.

My 1981 had an intermittent "start" position when I purchased the car in 2003. I installed a Bosch 40 amp contact rated relay between the ignition switch and the starter solenoid shortly after. I have driven the car 35,000 + miles since with no further ignition switch problem.

[70spider]

Well there in lies the problem, finding a new OE Sipea switch for a 124 Spider seems a bit difficult if not impossible. I know the Lada switch will work, for a time, but I like the idea Fiat is stamped on the key. The 850 Sipea switch looks identical but I can not be for sure, if those in the know can give me feedback on the 850 Switch that would be great.
As for now I am going to use azruss's method to test to see if my problem is difinatively the ignition switch.
As for doing something to the car I may regret if I sell it, no worries, I will never sell it. I tend to keep cars for 20 + years before I move on to another one. The way things are going (environmentally) operating a petro powered vehicle in the next 20 years will probably be outlawed, .

[divace73]

Well there in lies the problem, finding a new OE Sipea switch for a 124 Spider seems a bit difficult if not impossible. I know the Lada switch will work, for a time, but I like the idea Fiat is stamped on the key. The 850 Sipea switch looks identical but I can not be for sure, if those in the know can give me feedback on the 850 Switch that would be great.
As for now I am going to use azruss's method to test to see if my problem is difinatively the ignition switch.
As for doing something to the car I may regret if I sell it, no worries, I will never sell it. I tend to keep cars for 20 + years before I move on to another one. The way things are going (environmentally) operating a petro powered vehicle in the next 20 years will probably be outlawed, .

I managed to get some aftermarket ign switch from Greece or Egypt, don't know if it was LADA but is was no where as good as the sipea, I ended up cleaning my original switch (which also housed the door chime switch which I use to activate my radio). You can pull apart your sipea ign switch and give it a good clean and then install a relay to the starter motor.
here is the site where I got my info from http://www.mirafiori.com/faq/content/switch/ for the long screws I happen to find them in a hobby shop

The whole push button this however cool does puzzle me a bit, they had that in the 'olden days' then advanced to incorporate it into the ignition switch which would have been a sales pitch back then, amazing how things cycle around....

[70spider]

Thanks for the repair link. If the worst case senario happens I might just have to do that.

[nalle]

do you want to by pass the switch to test it or because you think the start position is bad?

I tried to bench test the pull in current for my 81 Spider starter solenoid and found it pegged the 20 amp meter on my bench power supply. Here is an interesting article on Starter solenoid operation and expected currents. I don't know if most Starter solenoids are of similar design but I would guess they are.

http://www.aeroelectric.com/articles/strtctr.pdf

Some auto and motorcycle manufacturers install a starter relay that has 30-40 amp contact current rating to protect the ignition switch between the ignition switch and the starter solenoid. A momentary push button switch capable of reliably replacing the start position in the original ignition switch would have to be physically fairly large.

My 1981 had an intermittent "start" position when I purchased the car in 2003. I installed a Bosch 40 amp contact rated relay between the ignition switch and the starter solenoid shortly after. I have driven the car 35,000 + miles since with no further ignition switch problem.

If I read right bosch schematic picture of starter they will recommend 25 A fuse for the solenoid.
http://www.bosch-automotive-tradition.c ... frame.html
On that picture is also explaind why some times you need to turn twice the ignition swich.
You'll have to register on pages to see the picture.

[azruss]

If I read right bosch schematic picture of starter they will recommend 25 A fuse for the solenoid.

The factory uses an awfully small wire for pulling 25a. May need that size for initial kick.

[nalle]

If I read right bosch schematic picture of starter they will recommend 25 A fuse for the solenoid.

The factory uses an awfully small wire for pulling 25a. May need that size for initial kick.

I have not checked the exact dimensions of that wire, but I estime that it is 2,5 mm2 or 4mm2.

Usually wires are chosen by temparature raise, voltage drop in wires is normally not the first problem (connectors are an other issue).
Standard says about wire installations (<1kV)

mm2 A (max, "covered inst") A (typical fuse) est. awg (mm2)
1,5 14 10 15 (1,65)
2,5 19 16 13 (2,62)
4 24 20 11 (4,17)
6 31 25 9 (6,63)

If the current appears only short periods, like starter, used current can be much higher. And if wire is "free" installed then we can also use higer currents. Values in the table are for continous currents.

Ofcourse with cars with 12V systems have to be more critical with voltage drop, but in cars wires are so short that it is not an issue. Reason for voltage drops are usually connectors and badly made joints.

I do not use normal "car" wires anywhere, I always use normal wires (insulation <1kV).
These wires has been made by standard, they have better inslulation (not so thin) and they do not burn (insulation) so easy if over heated.Price difference is minimal between the wires.
Here is the lin to the original table http://fi.wikipedia.org/wiki/S%C3%A4hk%C3%B6johto , i'm sure thet you'll find similar in english.

[spider2081]

For the solenoid wire between the ignition switch and the starter, I don't see a wire size on the older Spider diagrams I have. On the Diagram for 80-82 it shows a 2.5 mm which is like a #12 AWG. This size wire should carry 20 amps continuously. I believe most wire charts are for continuous current draw. The starter solenoid is normally energized for a few seconds so it would be considered a momentary current draw.
The surge current that lasts a few thousandths of a second causes the spark that can be seen when a switch closes. That is what eventually causes the pitting and burnt contacts making the switch intermittent.
Fuses are chosen to protect a wire from melting. I haven't tested it but I am pretty sure a 25 amp fuse would blow before a #12 wire would melt its insulation.
I to agree the terminals on the ends of wire also have current ratings. These ratings are often overlooked and the primary failure points are the terminals at the ends of wires. On the Fiats I have seen most of the factory crimps are good and intact but the terminal fails over time from environment and current. This is where most all the unwanted voltage drops occur.

With all of this we have to remember nothing is made to last forever. To have ignition switch problems after 30 years of operation is to be expected.