Fan goes on/off/on/off/on/off for about 5-10 seconds just after starting the engine and turning on the fan.
It's not everytime but has happened 1-2 times during the last 5 days.
I have dual climate. Display doesn't read anything out of the ordinary. Tried to turn up the fan speed while this happened and I could hear the fan increasing speed between the "off's".
Once working (after the 5-10 seconds) the fan works normally the next 30 minutes (the max I have driven at a time this past week).

Isn't it most likely I have a soon to be faulty heater motor (and not any of the other related electrics)?




*EXTRA QUESTION*
The only thing I really hate about my GP is the A/C not being allowed to turn on once outside temp-sensor tells the car that temp is lower than 0 degrees celcious.
Thought about installing a hidden flip-switch that directs the outside temp-sensor through another resistor. In this way I would cheat the car into turning on A/C even at minus degrees celcious.
But would I be in danger of damaging the A/C system if I turned it on in like -5 degrees celcious? I would understand if FIAT didn't want me to turn on A/C if it was -20 outside but, at least for now, that seems unlikely in Denmark.

Hi.
My 2012 behaves on start.up.. and I have not noticed the cold temp cut.off.

Maybe worth removing the fan motor..easy to be partially blocked with debris.

Charlie

Mine is 2010 (pre facelift).
Light in A/C button goes on when I press it but the A/C “frosty” logo in climate display is not present = A/C not on.

UPDATE: Just went for a drive. Fan speed clearly goes up/down in between (not only at startup). Changing so fast it’s impossible to hear if it’s fan speed going up/down or cutting out and on again?

Will try and disassemble the fan/wire setup behind the glove compartment tomorrow maybe...

Disassembled the heater fan and gave it 12V directly from an external source.
Seems like it spins well. Increased amps (from 0,5 to 1,5) via the source and it increased speed. After 10 minutes of nothing but steady sounding speed I decided to go for eBay and browse for a Climate Control Resistor/Rheostat. Look at link below => Either this one or a cheaper one including shipping to Denmark.

There was half a dry leaf and a few small minced bits of it in the fan but I doubt that could stop the fan from turning.
When I install the "original old" parts I will be sure to turn on engine + fan and wriggle the connectors. Forgot about that before I pulled out the heater fan


https://www.ebay.com/itm/Fiat-Grand...rentrq:9a0c872a1670add8e7b8102ffff2eefb|iid:1

Re-installed the original parts and turned up the heaterfan to about half speed.
Wriggled the cables at the Climate Control Rheostat and suddently fanspeed went up/down again.
Seems like I can provoke it by jerking a bit with one of the 2 large 12V plugs/cables.

If I pull any of the 3 plugs out of the Rheostat the fan stops turning?

NOTE: Fan does not at any time stop when I just wriggle the cables but just goes to a lower constant speed until I wriggle it to the other side again?

What the heck?... If I loose one of the connections I would assume that the fan would stop (as when I pull one of the 3 plugs from the Rheostat). What am I missing?

Maybe..?
The basic resistor gives;
3. 6. 9. 12. Volts to build the 4 speeds.

If you PARTIALLY lose 1 of these..connections will that not replicate your fault.. ?

I might be a little dumb today so not sure if I understand correctly...

There is what looks like a 12V cable (2 thick wires) going into the Rheostat and one 12V cable (2 thick wires) going out of the Rheostat to feed the Heater Motor.
Another much smaller plug (2 small wires) also goes into the Rheostat.

If I remove any of these plugs the heater stops completely.
If the plugs are in, turning the heater on at max speed and I wriggle to wires a bit the fan speed goes down to some low constant speed until I wriggle again?

See photo from eBay:
https://i.ebayimg.com/images/g/c4sAAOSworhb1iJp/s-l500.jpg

As you mention I guess it does replicate a basic resistor (from the non-climate 4-speed setup) but I just don't understand why the fan doesn't just stop when wriggling instead of changing to lower speed. It stops whenever I pull one of the cables. Well of course it stops when I pull the any of the 12V plugs (I get that!) but also when I pull the tiny cable that probably controls the damn thing

If the inner cable copper strands are damaged..

Dropping from @16 connected strands ..
To say 4 good strands after a wriggle..

Maybe that could add enough resistance.. loss of power to physically slow the fan.

Just an idea..

Of course... (stupid today as I said).

Tomorrow I'll cut a cable at a time as far up as i can get and replace and check (one by one).
Have tons of different cables at work so will just make sure it's as least as thick.

I noticed the cables where not run through the plastic cable hook (built into the heater fan plastic cover). They were hanging a bit low so any long leg passenger could have been kicking the cables... :/

... will be updated

I am far from an expert electrically..

But given the punto line has a vast history of bad heater wiring.. it seems an obvious starting point.

Personally.. I would check the plug connectors.. for heat damage.

Then change :repair the earth cable before the power ones.

Good luck..
Do let us know what you find.

My MJ has a poor plug connection..

I have now positioned at a weird angle ..where it currently works reliably

Hej,

punto and other assimiled cars has two main type of fan control:

- voltage divider through a set of resistors.
- PWM (pluse width modulation) through electronic control.

As being the 'auto climate' version, Your grande has the electronic fan controler (M072) and you observation of the plugs is correct: one feed (dual polarity) TO the unit, one feed FROM the unit to the fan motor (N085) and two thiner wires to bring the signal from the climate unit (M070).
When you wiggle the harness you're probably increasing the connection resistance that has build-up on one of the connectors, resulting in the fan speed variation. Of course if you disconnect any one wire the fan will stop because it's missing either power (plus or minus) or PWM signal …
Has the PWM signal connector carries only smal current it is not prone to heat damage, but the two others are !
Inspect them for brownish discoloration and you'll find the culprit; a good wire brush (or nail file) cleaning and a bit of plier-pinching the lug would probably help restore a good non-resistive connection …

BRs, Bernie

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Hello again (and you for the replies)!

Just got inside after testing the fix and seems like it's okidoki again.

Starting with the 12V between Rheostat/Resistor and the Heater Fan I used my much loved Fluke to check Ohm while slowly wriggling the cable. Noticed the resistance (via Fluke display) danced a bit from near zero to way up high so decided to start here.
Seemed like it was impossible to get the little "she"-connectors out of the plugs but luckily there was a tiny hatch on one side of the plug. Cut the old cables short at the plugs (in different length so I don't risk a shortcircuit when I gather it up with the flex-hose that I heat up to shrink - whatever it's called).
The little hatch enabled me to solder the new cable directly onto the metal she-connectors in the plug in each end.

Heater Fan speed seems to be steady now when I wriggle the cables a bit. I think I will install some kind og thin cover so passengers can't accidently trample og kick the cables.

Please excuse me for any bad grammar and mispelling. It's not often I write in English

And now to do something about that bloody outside temperature sensor. First of all bad connection in the plug in sidemirror. Info display dent from showing -27 degrees celsius to +7 degrees just by taking this plug apart and together again.
All looks fine but will try and clean it up with some contact spray and maybe put on some silikone stuff to keep i from getting moist. Before you ask => Nothing happens when I wriggle the cables around this plug so shouldn't directly be faulty wiring as with the Heater Fan.
Will experiment with a variable resistor once I locate which colors the outside temp sensor has (somewhere around where the cables enter the car near the passenger door. Haynes is my friend here. This way maybe I can (once below 0 degrees celcius) cheat the little big Italian into thinking it's warmer outside... and let me turn on A/C even if it's -3 :slayer:

>>> Will create a new thread regarding the outside temp...

Hej,

here is the drawing for the external temp sensor …

MvH, Bernie