HI, guys!
I have '95 Batchetta and a problem with heated rear window on my hardtop.
When I connect the heated window connectors, they get hot and start to melt. They melt and smell even when heating is off.
What can be wrong?

did you have the right polarity? (+/- around the wrong way?) can't imagine that would make a difference on the heating element. Apart from that sounds like its drawing too much power, perhaps there is a short circuit?

yes, the polarity is right - the heating works

it looks:

Maybe anybody had the same problem?

Possibly too little internal resistance. The circuit should have sufficent resistance in order for the heating element to heat up, too little would result in the heating occuring in the area of most resistance; in this case the connector where the prongs are made of thicker metal.

Suggest you test the resistance of the heating element, and maybe someone else on this board can tell you what the resistance of their rear screen is (I don't have a hardtop else I would...)

Mike.

could be that.perhaps some on the strips are broken cutting down the resistence of the element

get a multi-meter and see what the resistance is, and try and find out what it should be, either from the hood manufacturer, or the barchetta workshop manual, or even somebody from the punto section may be able to help you, it must be common to both cars too.

THANK YOU!
I'll try!

the result will post here

Hi iVan_sbk
Don't worry about how much current the heated sreen is drawing, it will draw what is needed. A heated screen of this size draws between 8 and 12 amps. Your problem is with the connector, the contacts look pretty small which means that they have to have optimal contact pressure to make sure that they do not start heating up due to the contact resistance with this amount of current. This is obviously what has happened ( FIAT electrics?!?! ). Once electrical contacts like this start to burn you just have to change them. Once the surface of the contact starts to burn, its resistance goes up and makes for even more electrical heating of the contacts ( I²r ). A vicious circle which could lead to an electical fire!! Since the heated rear screen circuit is probably protected with a 30 amp fuse, there will be enough current to do some damage before the fuse blows, if at all.
The answer to your problem is to cut off these two connector ends ( noting which wires go to which ) and replace with standard quarter inch flat blade connectors. Remember that there's quite a lot of current flowing so make a good job of it!

Chris C