I have pulled the blower motor sensor out today cause my battery was going down (new) every couple of days.
I read on the forum that this is a possible cause, but after i removed it and put it on a multimeter it tested ok, so i refitted it and low and behold it works (blower motor is working)….is this normal?

It could have been a bad connection which you corrected when you disturbed the connector.

The motor sensor is a common failure point. It relies on cooling to avoid it overheating and damage.

Mike

Is the blower mower what cools the sensor ? Or something else?

The sensor (or hedgehog) controls motor speed, hence the large heatsink.

If it fails, the blower motor will stop.

If your heating/cooling is working after removing and replacing the sensor, then all's good.

Mike

The sensor or final stage resistor as it is called is cooled by the airflow into the ac / heating system when the blower motor is operating. If they fail they usually result in the blower motor operating at full speed only.

I have had failing blower final stage resistors (or hedgehog or whatever you want to call it) really give me the run around.
Strange fan behavior is the giveaway.
Fan that won't go at all
Fan full flat out
Fan that won't turn off even with the ignition off (and flatten the battery)
Fan that has a mind of it's own.

Disconnecting and reconnecting the battery will often settling things down, but within a day or two it will be back to it's old tricks.

If you do replace it buy a name brand one like Mahle.
The cheap ones from Aliexpress are very tempting, they look exactly like the name brands even down to casting marks on the plastic,
and they do work, but you will only get a few months out of them before the above circus starts all over again Rob

nicedayforit wrote:

The sensor or final stage resistor as it is called is cooled by the airflow into the ac / heating system when the blower motor is operating. If they fail they usually result in the blower motor operating at full speed only.

robanzac wrote:

I have had failing blower final stage resistors (or hedgehog or whatever you want to call it) really give me the run around.
Strange fan behavior is the giveaway.
Fan that won't go at all
Fan full flat out
Fan that won't turn off even with the ignition off (and flatten the battery)
Fan that has a mind of it's own.

Disconnecting and reconnecting the battery will often settling things down, but within a day or two it will be back to it's old tricks.

If you do replace it buy a name brand one like Mahle.
The cheap ones from Aliexpress are very tempting, they look exactly like the name brands even down to casting marks on the plastic,
and they do work, but you will only get a few months out of them before the above circus starts all over again