strange electrical issue on my fiat 500L with 650cc...

[paganini]

:sad:

Hi fiat experts,

     I am facing with a very strange probelm, electrically...

1. fixed cylinder head and reconnect everything over the weekend, switching key, only dim green and red light...horn working; starter grinds but no ignition;
2. decided to jump with battery from my mini van after re-time and re-check sparks...ignition OK, and let car ran for 5-10 min.
3. switch off key, then try re-starting by battery, noda;
4. dim green/red lights on dash are now completely out, and so is the horn;

5. try re-jump with mini van battery, but no electrical juice to ANYWHERE???

I study the wiring diagram, and couldn't find anything suseptable to jumping the battery...must be something by co-incident with main wire somewhere???

another weird sign: after fully re-charge the battery, I will hear couple cracking weak noise when pushing the horn button, then completely silence like NODA is connecting.  switching key has no sign or battery either.

voltage meter the battery shows 13V, between terminals, and earth near front side of the gas tank...at least gound is good.

will check the back, but would appreaciate if any of you have other suggestion on debugging the main positive wire to the back, generator (or is it alternator with the 126 engine, has white plastic regulator attached?)

grazie

ciao

[ChrisRLewis]

sounds like a bad connection somewhere?

when you have the problem does it affect everything, such as headlights etc?

[paganini]

Hi experts,

     Like I mentioned before, no light, no horn (only low cracking sound for couple seconds after sitting and recharging the battery overnight) and no starter.

     Maybe I was so unlucky that BOTH wires went bad???  as far as I know from the schematic (I'm good at IC circuits) lights and horn are from term 30 AND same live wire of STARTER, then pass to the fuse box.

     In reality, there is NO common breaking point for those 2 wires.  I am very anxious to get to the bottom of the cause, and I will keep you all posted.  But it is just a very strange happening, all at once, after a successful jump start....

     BTW, there is NO shorts anywhere to the positive.  And grounding of the front portion of the car is perfect.  Will check the back end soon...

ciao!

[ChrisRLewis]

I would suspect it's one of the main power cables or earth connections. Battery clamps ok?

Have you tried manually operating the starter motor with the lever which is on the starter motor? if it's dead it's got to be the main power connections?

Also do you have a separate earth lead from the engine to the body?

[phreak97]

i've seen things like this with oxidised battery terminal clamps, usually i get a fine round file and file them out until theyre shiny, then go around the battery terminals with a flat file (watch you dont short the terminals, bad stuff happens). amazing problems can occur from bad battery connections. most common i've seen is all lights ok when i turn the key, then as soon as i go to start it, i get a click then everything dies, no lights, not even an interior room light. i think i understand why, but im not going to go into that much detail.
give them a clean up to at least rule it out.

[bis13]

i take it your have a manual starter ? if so then remove the battery and rig up a temporary loom to miss all the front loom out (so that it feeds only the essential engine components ). if it runs ok its a problem at the front so you know where to look .

are you using a alternator or dynamo? is the voltage regulator working okay?

[paganini]

thanks guys for some good info...I finally have fixed up everything on the little rascal and it is running with nice idle and good starting.

just one last question, should the 650cc be blowing some air out near the area of the throttle linkage rod.  at first I thought of the small area in carb that is leaking, but patched it to have steady idle.  but now I still feel the air (could be cooling air coming around the engine?)...maybe it is OK?

in any case, in turns out to be that my horn would have problem if 2 of the wires somehow dangling in the back of the ignition switch.  once I pull them our completely, the horn started working.  now I fix them back, the switch is OK, and so is the lieve battery feed to the starter...and I am almost in complete business, minus the cooling air flow issue mentioned above...

grazie,

ciao!

[bis13]

the air leaks out between the motor and tinwork, originally the tin had a gasket sort of thing but seems to go missing dont worry about a little air going through small gaps as there is plenty more going to the engine to cool it and dont forget it gets a lot more as the engine revs higher and the fan turns quicker.happy driving

[ChrisRLewis]

does it still occur if you close the heater control flap located at the rear tunnel?

[paganini]

I have been busy in doing other things...but the good news is that the 500L is now moving right along, minus other nuisances...

the electrical issues are almost all fixed except I can't seem to add another horn to the existing one...very small sound.

still sort of feeling air when heat vent is close...the other day, I had a lot of oil spitting out from the rocker gasket due to over-tightening or bad material, I felt smoke coming into the front but fan is also blowing out to the rear as well...no biggie here?

what is the smallest tubeless tire/rim that I can sub for the original 500L? somewhere I got 5.5x13?  minilite?

is there any electrical starter exist for the 650 engine in 126 or 500?

sorry for appending to the original post...but I think it maybe easier for everyone to ref to?

tx.

ciao!

[phreak97]

theres definately an electric starter motor for the 126 engine, mine's a key start from factory, i assumed they all were.