Technical Idle too high

[the hobbler]

What model 500 do you have? If it is a 500D, according to my 'Factory' book-of-words, all fuses should be 8 amps. Also, the photo you have shown does not match the wiring diagram you have shown. According to the photo, the 2nd wire down on the right of the fuse box (and it should have an internal connection to the top terminal) should be green (verde), and go to the 'Outer lighting switch'--there is no wire to the top right terminal. Lastly, the bottom right wires should be red (rosso)--1 goes to the positive side of the battery, the other wire goes to terminal 30 on your ignition switch (lock switch in 'Fiat-talk'). The wiring diagram you have shown does not have this battery/fuse-box feed and diagram is possibly for the 500R. I am NOT an electrician, but having just had to sort out the wiring on my 500 after it came back from the body-shop (with, let me add, a great deal of assistance from my son who is far more 'electrical' than I am) I have suffered similar problems!

 

[Bigvtwin996]

hard to say what a high reading is...
but if you measure a simple piece of wire....
then anything above that will be high...
but it is more a case of noting that you get no or erratic continuity either side of a component or connector... worse when the connector is wiggled...
I have a set of leads with crocodile clips on so I can attache the meter and wiggle stuff... when set to the audio "buzzz" it should remain constant..

As Tom has said what car?.. it's not and N or D because the speedo is held in with Push clips... on the speedo body...You need an accurate Diagram for the car.

it does seem to have a bit of a mix of switches etc.. round and spade terminals....
Time for a tidy up I think...
It could actually be something in the Steering column controls shorting out....

Really hard to fathom, but sort the fuse box out and make sure you have power to the other side of the fuses......

If you are not sure then get someone to help.. or things can melt..

 

[AndrewHarvey]

Fuses definitely 8 amps throughout. Use the diode symbol setting on multimeter for identifying earth connections and checking fuses.notek Use the 0.00 v dc setting for finding a 12v feed. Check that voltage appears both sides of fuse. The fuse box type shown are famous for having loose fuses / voltage problems.

 

[Bigvtwin996]

personally $38 + $9 shipping.. (Mr Fiat as you are in the US)
I'd simply put a new fuse box in to start...
and new fuses..
clean up the connectors and label them...
nothing fancy just 1-6 each side with a bit of masking tape..

 

[turbo500]

Fuses definitely 8 amps throughout. Use the diode symbol setting on multimeter for identifying earth connections and checking fuses.notek Use the 0.00 v dc setting for finding a 12v feed. Check that voltage appears both sides of fuse. The fuse box type shown are famous for having loose fuses / voltage problems.

Yep I have 8a fuses coming in this week. It's a 500F as some of you have correctly spotted. I might end up getting a whole new fuse box and maybe even a new wiring loom

When you mention to use the diode mode, is this always with the battery disconnected yes?

I've done a continuity test on almost every cable/bulb/fuse and they always come back buzzing. So unless I'm doing something wrong on the multimeter, or the cables are in the wrong places, I don't get whats going on.

 

[AndrewHarvey]

Continuity mode is fine.
Get thr correct wiring diagram and enlarge it on photocopier/ scanner.
Trace circuits from fuse box. One side of fuse is supplying the voltage. (Feed) take single fuse out to find which side is live with ignition on.
Other ( load side ) is feed to power some thing. Use continuity from fuse box load to cable end at item to check- beep identifies this as found.

 

[Vitesse]

I would measure for 12v DC voltage at the lights that you have problems. On the bulb the centre pin of the bulb is the 12v +, so stick your multi meter red lead inside the bulb holder to where the centre pin of the bulb would make contact when it is in situ. On the license plate there is only one wire, that is the 12v, so it should be 12v when the lights are on. There should be a wire that you can unplug when you remove the engine lid, unplug it put you red lead of the multimeter on it and the black lead to the earth, the engine block.

The black lead of the multimeter needs to go to a decent earth, in the engine bay try touching it to one of the nuts holding the dynamo to the engine block. In the bonnet area, there is a nut holding the flasher unit to the cars chassis up behind the fuel tank or on the fuel tank there should be a black wire going to one of the 8mm nuts that bolts the fuel tank level sensor to the tank.

In my opinion it's highly unlikely that it's going to be a fuse box issue, as you have all the main lights and indicators working, all the lights you have problems with are just subsidiaries of their main circuits.

Tony

 

[turbo500]

Hi Tony,

Thanks for the explanation. I did two tests, one with the license plate light (right at the connector, witht the bulb pulled out) and it came back with a reading of ~10.4v

The other one was the done with the speedometer lightbulb housing, removed the bulb and it came back again ~10.4v. I put the bulb back in, and tried to get a reading but it was all over the place. Continuity was good though, and flipping the light switch didn't seem to make a difference??

Anyhow, I've ordered new bulbs, new fuse box, new wiring loom, and will initially start to change all bulbs just to see if there was a problem with that.

I will also retest when I get the correct fuses in.

Thanks for the help guys! Really appreciate it

 

[turbo500]

So as I wait for my parts to arrive, I was wondering what grease to use for the 500.

Is there a specific type I'm looking for, or is a general 'wheel bearing' grease ok?

These are what's available:

[ame]https://www.amazon.com/Mag-720-High-Temp-Bearing-Grease/dp/B0077K8WJC/ref=sr_1_2?ie=UTF8&qid=1500592272&sr=8-2&keywords=wheel+bearing+grease[/ame]

[ame]https://www.amazon.com/Valvoline-SynPower-Synthetic-Automotive-Grease/dp/B000GAN3I0/ref=sr_1_3?ie=UTF8&qid=1500592272&sr=8-3&keywords=wheel+bearing+grease[/ame]

[ame]https://www.amazon.com/Allstar-ALL78241-Timken-Premium-Bearing/dp/B006K8VIAM/ref=sr_1_4?ie=UTF8&qid=1500592272&sr=8-4&keywords=wheel+bearing+grease[/ame]

[ame]https://www.amazon.com/Lucas-Oil-10330-X-Tra-Grease/dp/B000IG5QOQ/ref=sr_1_8?ie=UTF8&qid=1500592272&sr=8-8&keywords=wheel+bearing+grease[/ame]

I think they are all #2 lithium based, from my limited knowledge it seems ok.

Any thoughts?