1981 Fiat Spider continued issues electrical

[Fiatbrit]

Hello,

My 81 Fiat Spider continues to act strange. It sat for awhile and i cleaned the fuses. It started right up and i thought I found the issue. I drove it several times without an issue and then tonight it started doing the same thing again. It starts and then randomly will quit. The fuel guage and temp guage quit working at the same time all other items keep working, lights, radio, power windows and ect. the car always turns over but when it does this I need to keep turning off and on the ignition switch. When the guages come back I know it will start, runs for random amounts of time and then will quit again. I hear the relay click and the engine stops guages drop to zero at the same time. What connections do the ignition, fuel guage and temp guage all share that I could inspect?? It must be a bad connection somewhere that acts so randomly. Any help would be greatly appreciated it is making my nuts. It has a new dual ignition relay and the AFM is newly rebuilt. Please advise and thanks again.

[vandor]

Sounds like an intermittent problem in the ignition switch. One of the two main circuits disconnects.
You can verify by checking the wiring diagram to see if the gauges and EFI are powered from the same circuit on the ignition switch.

[Fiatbrit]

Hello, thank you. How can I tell if they share the same circuit as you mention. Please confirm. It did seem like occasionally if I wiggled the key I could get it to quit but it is so intermittent it is hard to say. How hard is it to switch out the ignition switch? Please advise and thank you

[baltobernie]

http://www.youtube.com/watch?v=G39ot4hKKyQ

[vandor]

>How can I tell if they share the same circuit as you mention

Look on the wiring diagram to see if both of those circuits get powered by the same wire from the ignition switch.
FWIW the ignition switch has two circuits that get switched on when you turn the key on, and a third one for the starter.

You can find diagrams at: http://www.artigue.com

[Fiatbrit]

Thank you for all the help! Looking at the wiring diagram for the instruments it appears that all the instruments are fed off the white wire on the ignition switch since that is the only wire shown on that page. Would that be accurate? Other items still seem to work such as the power windows when the car quits and they show on the same diagram grouping. Does this rule out the ignition switch?? Please advise

[vandor]

You need to look at the other pages too and see what else is fed from the same ignition switch connection.

[spider2081]

I agree it is likely associated with the ignition switch circuit. I would inspect and clean the ignition switch connector. This connector is a common problem area and often overheats making poor connection. Also if you have a trouble light check the black wire on the ignition switch. This is the "hot all the time" wire that feeds the ignition switch and then the circuits you are having problem with. The pink wire out of the ignition switch feeds your problem circuits when the switch is in the "start and run" position

[Fiatbrit]

Thank you, to clean the switch connection should I pull the white plastic connector apart and try to sand the spades? I also have some electronic spray cleaner. If that fails I imagine I need a new switch since it is likely internal to the switch but my guess is the connector too since my test light indicates power at all terminals (accept start position) whe key is on even when gauges are out. Also I noticed the black smaller wire with in line fuse falls out of the fuse holder. Doesn't seem to make a difference on gauges or running but must take care of another circuit? Seems to be original to the car? Please confirm. Thanks to all who have replied this is truly a GREAT site!!

[spider2081]

Often when the connector is a problem you can see a brownish color on the white nylon connector. Also the pins will loose their silver color and become a darker color. I like to test the female pins with a male pin purchased from a local car parts store, Insert a male pin into each of the female pins one at a time. it should be fairly hard to push the male pin into the female sockets. If the socket has been over heated it will expand. The male pin will feel loose in those sockets. They can be tightened by squeezing a little with needle nose pliers. If you make them too tight you will not be able to get plugs back together.
The 1981 Wire diagram I have does not show any inline fuse holder connected ignition switch connector. Maybe a previous owner added it.
If you have a volt meter it might help. The battery voltage should be present on black wire all the time and the pink wire in "run and start" If there is less voltage on the pink than the black it would be the ignition switch that is bad.