Technical heater resistor, where the hell is it???

[chrisbonnie]

my heater resistor is dodgy on the doblo, so, being fairly handy, i bought a resistor and am now currently trying to install it, i have the heater panel all off, but the part i have, is definetly not behind the heater switch

any ideas lads???

my van is sitting in the garden now with half a dashboard :yuck:

 

[chrisbonnie]

anybody?

 

[db1]

i had to join the forum just to answer this question. lol
it,s up in the passenger side footwell [rhd] behind the glove box,
it,s a brown unit held in place with one screw

 

[chrisbonnie]

i had to join the forum just to answer this question. lol
it,s up in the passenger side footwell [rhd] behind the glove box,
it,s a brown unit held in place with one screw

ha ha, cheers, took less than 2 minutes, a warm cab sure is nice

 

[db1]

today spent six hours sorting my heating out, replaced resistor[no joy]
tried another fan speed switch [no joy].
so out with the multi meter tracing the lack of voltage as the blower was ok when dc to 12 v something was not right :bang:
i eventually found a over heated connection and spent 20 pence fixing it.
not forgetting the £43 on bits i did not need but i did not pay for diagnostics as i sorted it my self so

 

[dgary]

Hi,
new to this forum but it looks useful. I am replying here because it seems I have a similar problem. Heater fan was operating intermittently and has now effectively failed. This is combined with the dash lights around the heater controls behaving oddly. They come on with the ignition but go out when the vehicle lights are turned on. This suggests an earth fault to me.

db1 - can you please advise where you found the over-heated connector? I have looked at all those I can find in the passenger footwell and there is no obvious fault. Does anyone know where these circuits are earthed, please? Is there a local earth under the dash somewhere?

Thanks
dgary

 

[dgary]

Ok, after posting that question earlier I have searched further through the Forum and found many references to problems with the heater fan in many different Fiat models.

This one is probably the best in the way of an answer and fix - https://www.fiatforum.com/punto-guides/170894-mk2-my-sidelights-come-instead-my-interior-fan.html - but all point to a similar cause.

All the problems seem to relate to inadequate components in the wiring loom. The current passing through this particular connector is too much for it unless (perhaps) it is in absolutely perfect condition. That is, after a few years and a bit of corrosion, the current-passing capability reduces, leading to a build up of resistance and heat and the melting of the plug/socket and adjacent wiring! In my case the black and blue (heavy) wires either side of the connector were melted together due to the insulation having become sticky at high temperature.

For the time being I have separated the wires and wriggled the connectors (they wont come apart) and the fan is working OK. We will see how long it lasts!

It strikes me that this is a fire hazard and something that Fiat ought to be know about and to be doing something about - in their newer models even if not retrospectively.

Cheers
dgary

 

[db1]

sorry for the late reply. the connection that caused me problems is up by the heater fan motor it has a blue wire in the middle this is the one that overheated and melted part of the plug connector. it does come apart but not
easily. there are 2 fuses for the heating system that never blew .

 

[dgary]

I wouldn't expect a fuse to blow in the circumstances I have and have seen repeated in various postings here.

I reckon that the problem is not 'over current' (which should blow a fuse) but local high resistance which creates excess heat.

It seems that the connector is only capable passing the required current when it is shiny and clean. Once it gets a bit damp or corroded, the capacity drops and the resistance builds up, leading to heat. The problem is that heat only makes matters worse and increases the corrosion.

Mine is running OK at present after giving it a good wriggle to agitate the connectors and increase the connectivity. however, I shall be looking for a new connector to replace the melted one.

cheers
dgary

 

[db1]

i understand very little about electrics and have only recently purchased a multimeter read the manual [was still confused]and found the problem.
and by passed the connection with a bullet type connector [male & female].
i am glad that i did not have to pay for a auto electrician.

 

[tallpaul1972]

i`m glad to have found this thread as i`ve got the samo problem with my 1.2 multi jet ,, but sorry to ask guy`s but i`m a complete numpty and dont even know were to find the cables that are the problem so could you give me an idiots guide ,,, many thanks

 

[paul brava]

it`s basicly under the glovebox(rhd) get the new one from fiat give them your reg no tell them if you have air con ,you get the new one get under the glovebox with the new one and you can see were the old one is as you have the new one in your hand take the two screws out drop it down take the electric plug off put that on your new one scraw it up and your done

 

[mickleplum]

Ok, after posting that question earlier I have searched further through the Forum and found many references to problems with the heater fan in many different Fiat models.

This one is probably the best in the way of an answer and fix - https://www.fiatforum.com/punto-guides/170894-mk2-my-sidelights-come-instead-my-interior-fan.html - but all point to a similar cause.

All the problems seem to relate to inadequate components in the wiring loom. The current passing through this particular connector is too much for it unless (perhaps) it is in absolutely perfect condition. That is, after a few years and a bit of corrosion, the current-passing capability reduces, leading to a build up of resistance and heat and the melting of the plug/socket and adjacent wiring! In my case the black and blue (heavy) wires either side of the connector were melted together due to the insulation having become sticky at high temperature.

For the time being I have separated the wires and wriggled the connectors (they wont come apart) and the fan is working OK. We will see how long it lasts!

It strikes me that this is a fire hazard and something that Fiat ought to be know about and to be doing something about - in their newer models even if not retrospectively.

Cheers
dgary

Thank the lordy I fund this post - once again the forum came to the rescue. Basically my heater problem was exactly as described and found the said plug where it should be .. Snipped the bugger and connected with a good old connector block etc ... So I won't have to drive another 2000 miles in sub zero temps with no freakin Heaters ....

230,000 miles afore it buggered up tho.. so I can't complain ....

 

[murphyv310]

Hi.
I am a TV engineer to trade (not doing it now due to lack of work) and I cannot believe the low quality of the Electrics/Electronics on Fiat's. I have spent some considerable time on my Doblo improving wiring, bad earths, cable runs, and all sort of problems caused quite simply by bad workmanship.
I really am surprised that there are not more problems with the electronics.
The other thing that bothers me is the cost of parts. My last car was an Audi 80 and the parts for this was a fraction of the cost and even dealer parts were cheaper and of course much better quality with a longer life.

 

[T14086]

you in a bad mood tonight Trevor

IMO the electrics are ok when built but as wear & tear takes a hold after a few years things start to go wrong!