General Classic fiat 500 L 1970 - electrical dashboard issue

[chiarapapa]

Hi folks,

I have a bit of an ongoing issue, it happened since I changed the battery on the car.

The indicator light on the internal dashboard stays permanently on when the engine is running, the indicators on the exterior work as they should, and when activated they flash as supposed to.

I suspect there is a short somewhere but I can't see any obvious issues, any guidance would be welcome?

 

[Bleeding Knuckles]

Hi, I would check and clean all the connections on the flasher unit and then the ignition switch, if the light is Only staying on when the engine is running you may have a short in the ignition switch and/or indicator stalk connections.
Ian.

 

[chiarapapa]

Hi, I would check and clean all the connections on the flasher unit and then the ignition switch, if the light is Only staying on when the engine is running you may have a short in the ignition switch and/or indicator stalk connections.
Ian.

Hi Ian,
Thanks for that. I will have a look at your suggestions.
I've noticed the grounding terminal cable off the battery is looking a little frayed. Is it possible that could have something do with the issue?
Thanks

 

[Bleeding Knuckles]

Hi, with these cars never discount anything and change the negative cable.
Ian.

 

[chiarapapa]

Hi, with these cars never discount anything and change the negative cable.
Ian.

Good point!
So I swapped out the negative cable, checked the connections on on the flasher unit and ignition, it all looked fine. Also gave them a clean whilst I was at it. Checked the fuses, plus all the connections into the fuse box. Also checked the connections going into the back of dashboard. Basically any connection I could see I checked and cleaned. Wires also looked in tact, no open wires that I could see. I've also just noticed the main bulb light on the left headlight is not working. The bulb has been replaced with a new one and it still doesn't work, fuse is fine and the connections look fine also. Now I have 2 electrical issues. Not sure if they could be related?

 

[Goldnrust]

The headlight and indicators should be on very different circuits, but they are both controlled by the column stalks. Might be worth a quick check to make sure there’s no chaffing of the wiring from the column switches that could be causing a short?

Have you got a wiring diagram and multimeter? Trying to trouble shoot electrical issues like this without them is very much flying blind. A connection or wire can ‘look fine’ but with vehicles of this age internal corrosion or fractured wires can make for hidden issues. The only real solution is to methodically trace the signals (12v or earth) through the wiring loom till you find where they go missing.

 

[chiarapapa]

The headlight and indicators should be on very different circuits, but they are both controlled by the column stalks. Might be worth a quick check to make sure there’s no chaffing of the wiring from the column switches that could be causing a short?

Have you got a wiring diagram and multimeter? Trying to trouble shoot electrical issues like this without them is very much flying blind. A connection or wire can ‘look fine’ but with vehicles of this age internal corrosion or fractured wires can make for hidden issues. The only real solution is to methodically trace the signals (12v or earth) through the wiring loom till you find where they go missing.

Hi Goldnrust,

Yes, I have a wiring diagram and multimeter. I'm learning as I go.
Yes, I believe they are on different circuits. Good point about them both being controlled by column stalks. Although if there was a fault I imagine both headlights would fail in that scenario. I am getting a low voltage reading from the black wire going into the connector to the bulb. So it could be a corroded connector, but I haven't had a chance to trace it back to rule out the wire itself. So will do that later.
Which 'could' mean the 2 issues are unrelated.
Regarding the indicator light staying on, on the speedo/dash. I had a little wobble on the column stalk and what little wiring I could see and poke around. The light intensity fluctuated very mildly as a result of that. So I guess I should investigate further? Assuming the wiring goes straight from the stalk into the speedo. How do I go about accessing it? I could not see any screws or clips behind the speedo in the bonnet compartment. Any insight to that would be appreciated?
I hope I'm on the right track, as mentioned I'm learning as I go.
Thanks for your help so far

 

[Goldnrust]

The headlights are are two separate circuits, with separate fuses, and separate wiring from the column switches.

If wiggling the stalks makes a difference, I’d definitely investigate where the bunch of wires from the stalks go through the dashboard, they could be rubbing and shorting out on various sharp edges.

I’ve only experience with the ‘F’ round speedo, which has metal press fit clips, maybe someone with an ‘L’ can help with the speedo removal. With the speedo out, you should have much better view of the wiring from the stalks as it goes into the under bonnet area.