How to fix the heater blower resistor card.

I have just fixed ours, so thought I would share the info.

The little 'blob' on the resistor card is solder.
I believe that this is designed to melt in the event of the blower motor drawing too much current. It is acting as a fuse.

What appears to happen is that the card gets damp and the joint to the sodler blob corrodes and looses contact.

Scrape about 5mm either side of the blob with a knife to expose the copper track.
Put plenty of solder on one side.
Do the same on the other side and keep adding solder until the 2 side join together.

I don't think that this will cause any problems, as the joint is still solder which can melt.
However, follow these instructions at your own risk.

It is probably a good idea to remove and check the blower motor is not stiff.
There is a black plastic cap on one end of the motor.
Remove this and lubricate with a little oil. Just 2 or 3 drops.
I used vegetable (cooking) oil which has no smell.
 

Bence_Fs

Wha Tank
Club Member
Did you take any photos whilst performing this fix?

nice one mate, could save people a fair bit of money

ive had 2 mincras and the heater cards went on both of them
 
I've found a tutorial, however its not very descriptive :/ Will keep looking :)
its really not that difficult, did mine at the weekend there

under the passenger dash right in the footwell there is a bit of plastic being held in with two screws and some wires going into this
unscrew and pull this out
there will be bits that are rusted or burnt, sand them down but be careful not to sand the rest of the board or tracks
the main problem is usually a small rectangular bit which is the resistor, it will stand out as its bigger than the rest of the tracks
once sanded down to show the contacts simply solder across to complete the track (or some have said conductive paint also works)
apparently covering it in grease is a good idea to stop further rusting
then simply plug it back in again
 

frank

Club Member
the resistor card gets very hot on setting #1 (because its dumping max amperage there) which helps to demist the screen on cold engine startup.
mine now has a brushless fan motor, which uses low amperage at slow speeds (less wastage :))
 

skymera

Brutal Honesty
the resistor card gets very hot on setting #1 (because its dumping max amperage there) which helps to demist the screen on cold engine startup.
mine now has a brushless fan motor, which uses low amperage at slow speeds (less wastage :))
What do you mean?

I thought the resistor card was just fan speeds?
 

frank

Club Member
What do you mean?

I thought the resistor card was just fan speeds?
yeh, a high resistance for fan speed #1 then a lower resistance for #2 etc (and no resistor for #4, hence why you get #4 only when the card is duff) :)
and it was mounted down there in the ducting so that the airflow stops it overheating
my brushless one only uses a trickle current on low speed, and a higher current on high speed (plenty of motor heat and airflow on a cold engine startup)
 
I like cake.

I will attempt the card clean, however I am more prone to get a new one (just to have someone to blame when it breaks aha)

Thanks guys :) !
 
Frank, thats interesting to know your using a brushless fan motor!! Can I ask from what car was the brushless fan taken from please and is it a direct swap or was there any mods to fitting this motor??

Cheers

J
 

frank

Club Member
Frank, thats interesting to know your using a brushless fan motor!! Can I ask from what car was the brushless fan taken from please and is it a direct swap or was there any mods to fitting this motor??

Cheers

J
just a chinese duct fan and speed controller J (aeromodel jet thingy) binned all of this and then mounted the fan onto the matrix

PA100169.JPG
 
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