Heater resistor thermal fuse.

[Huzzah]

This one's in a Dacia Duster but the same setup as a mk2 clio, probably many others too.

It's a regular failure point, (thermal fuse) anyone come up with a satisfactory solution?

[_Rodders_]

make sure the pollen filter is changed regularly but they do seem to be a consumable.

[Jo-say8k]

Is it for the blower motor?

[Huzzah]

Yes blower motor, and I'll swap the cabin filter this time too.

This will be the 3rd one tge car has had, 1st one under warranty @ 2yrs old, 2nd one I replaced after another couple of years, just failed again. Car about 6 yrs old.

Edited by Huzzah on Wednesday 14th October 15:16

[Panamax]

Do you park outside? Are your windscreen scuttle drains blocked? Water can build up and overflow into the blower motor. The motor still works but draws a lot more current and will burn out the speed control resistors or thermal fuse.

If you need a new blower motor it's often a right pita, buried high up behind the dash.

[Huzzah]

Panamax said:

Do you park outside? Are your windscreen scuttle drains blocked? Water can build up and overflow into the blower motor. The motor still works but draws a lot more current and will burn out the speed control resistors or thermal fuse.

If you need a new blower motor it's often a right pita, buried high up behind the dash.

Yes we park outside, but keep scuttle drains clear.

[Panamax]

Huzzah said:

Yes we park outside, but keep scuttle drains clear.

So when you pour a watering can onto the windscreen the water immediately drains out from the right places under the car?

If it doesn't come straight through, the drains can get blocked lower down by an accumulation of powdery crud which makes it through the coarse grid in the scuttle and forms itself into a plug.

Hopefully it won't be this, but it's worth checking.

[Huzzah]

It drains really well thx, we have pine trees, so something I get a bit paranoid about!

[ExpertCarCheck]

Third one in about six years makes me think the resistor is the victim rather than the cause. A couple of things to add to Panamax's and Rodders' points:

The motor itself. As a blower motor's bearings wear it takes more current to spin, and the resistor pack and its thermal fuse take the extra heat. A new resistor on an old motor will often work for a while and then go again. With the resistor out you can usually reach in and spin the fan by hand. If it feels rough, tight or slow to run down, or squeaks on low speed, I'd change the motor and resistor together this time.

Airflow over the resistor. The resistor is normally mounted in the air stream so the air going past keeps it cool. Anything that cuts the airflow makes it run hotter: a clogged cabin filter, or debris in the fan housing. With pine trees around, it's worth looking into the fan cage and the housing for needles while the resistor's out, as they collect in there and slow the fan.

The plug. Check the connector on the resistor for browning or melted plastic. A poor connection there adds heat right next to the fuse, and if it's cooked a new resistor in the old plug won't last. Repair or replace the plug if needed.

If all of that's fine and it still pops, measuring the current the motor draws on full speed and comparing it with a known good one would settle whether the motor is the problem.