(T) water temperature max. for 5 seconds + beeps

Have you checked the earth points on the battery /chassis and gear box there has been a similar problem on the Grande Punto section


http://www.fiatforum.com/grande-punt...at-what-2.html


Dont know if its of any use to you but its always the case you do the most complicated things first and when it all boils down its the simplest of things...

Thank you Andy for this hint - I never look on the Punto chapter of this forum so i missed this one....
It all seems plausible reading this post - however i already replaced my battery by a larger one (60 Ah to 74 Ah) and never experienced this problem with my "low" model instrument cluster...
The part which wonders me is the drop of the 5 volt supply of the temp. sensor - the 12 volt battery voltage may drop while starting but the built-in voltage regulator should maintain it's 5 volt as long as the battery voltage doesn't drop under 7-8 volt??
the problem also occurs if i don't start the engine so i guess this is caused by something else...
But of course i will check the earth connection of the engine and gearbox - as you say most faults are caused by minor things like bad connections , low battery voltage etc.
thanks for your help, i will continue my research.....
yellowstilo

no problems i had it on my GP anyhow to cut a long story short i cleaned the earth post, clamp, eyelet crimps and earth posts smeared them with a bit of copper grease and put back together and the problem went away

its not the fact that the battery is low on charge its the dirty/ corroded/oxidesed (spl) contact that gives a high resistance path therefore reducing the voltage/current carrying capacity even though there is a voltage regulator if it cant get enough power to begin with the voltage will drop

(i think )

thanks Andy,
i will clean the earth strap from battery and engine, will post results when done..

Well, today I found a way around the annoing beeping when turning on the ignition or starting my 1.6L Stilo with the Abarth instrument cluster instead of the "low" version:
as i expected this to be a timing problem i built the delay circuit which is normally used for retrofitting a Connect Nav.
I changed the capacitor on pin 7+6 of the LM555 from 100uF to 47 uF to decrease the delay time.
I cut the dark blue wire of the cluster (switched 12v) and put the delay circuit in between these two wire ends.
I attached the earth of the delay circuit to the black wire of the cluster (earth)-
after some experiments i found that after 1-1,5 seconds delay the cluster doesn't beep anymore, the "checking" and "check o.k." are shown and the car runs fine.
As the body computer does 3 attempts within 4 seconds to check if all nodes are present this is not a problem.
Although the pointer of the temperature gauge still moves to "very hot" for a few seconds and the text "cruise control activated" is still shown at start-up i'm glad i can start the car without the 3 annoing beeps....
I realise this is not the final solution but it's not that urgent anymore to find out where this comes from....very rarely the car shows normal reading of the temperature but i can't find a relationship yet.
Of course i will continue to search for the cause of this annoing fault but if it can't be found this may be a solution for other Stilo owners with similar problems.
I will keep you informed about my progress...

yellowstilo