Blower resistor card fix

March Hare

March Hare

And another thing...
I finally got fed up with having all or nothing on the heater blower, after living with it all winter.
So I bid on one on ebay, and then found a guide to fix mine.
It is a REALLY easy fix - 15 mins at most.
The card just contains 4 strips of metal to conduct the electricity, of varying widths - the narrower the strip, the more resistance, the slower the fan.
All except the widest (full power) pass through a blob of solder designed to act like a fuse. What happens is the card get damp, and over time it corrodes (rusts) and the solder drops off. All mine had was a rusty spot where it used to be. (There was also rust appearing around the edges of the card.)
So I scraped off the worst of the rust, and also scraped back the plastic coating either side of the spot about 4mm to expose the metal strip. Then I simply soldered a blob on each side, with a bridge of solder (wire would do) to join them again.
I also wrapped the card tightly in gaffer tape to prevent further corrosion before refitting.
HEY PRESTO it works!
If you were really careful, this could be done with just gaffer and no solder, simply tape down a strip of wire.
Annoyingly, I am still the highest bidder on the card on ebay which i no longer need :(
######, what a waste of money! Anyone need a card...?
 
But the heater resistor is designed to be in the airflow to stop overheating and burning out earlier (as they get quite hot!) so surely the gaffer tape is going to cause the card to run hot?

Also, if the soldered bit is on the 'fastest' speed circuit and its the bit that falls off, why does the heater fan still work on the fastest setting when the resistor goes faulty?
surely a break in the circuit will stop the motor working on the fastest speed?
 
Not sure about the gaffer tape either.
I fixed our resistor by resoldering the blob.

The resistor is only used on speeds 1 to 3. On full, it is bypassed.
 
how much you looking for the resistor card? i don't have access to solder equipment so easier for me to just buy another card.
just about every micra i've had or family have had have all had this problem with the blower.theres only my mother in laws' 02 plate one thats fine,maybe cos its always kept garaged so doesn't get damp outside.. and its quite common fault too on older mondeos, mk1+2's. had a few of these too with blown resistors.
 
Definitely shouldn't cover the resister card in anything. Its deliberately in the airflow to try and keep cool.
 
Ok, maybe you all have a point about the gaffer, perhaps I should take it off again.
Is it definitely in cool air flow, not heated?
Incidentally, the strips on the micra card I bought take a much more complicated route around the card than my march one, although the blob is in the same place.
Also a common fault on older Rovers. Never happened to any of the multitude of french cars I've had though.

MikeOC, it cost me £20 including postage, I'll pass it on for the same. Pm me.
 
thanks anyway but managed to get one now....
but,i'm having trouble finding where the damn thing is in my car?? haynes manual is a bit vague in describing,just says located at bottom of heater casing-which is where exactly? it goes on about taking out parts of the dash to get the heater out,i don't fancy doing that as i'm no mechanic and i need the car for work so can't afford for it to be in bits...i've looked under the footwell best i can to try and see it but i can't get right down to look up inside very well- any advice please on exactly where it is and what the plug etc looks like so i i can try and spot it? the car is a 51 plate 1.0.
 
Under the dash on the passenger side!

Look under the dashboard, you will see a long brown plug. Take the screws out either side and the resistor card will slide out.
 
Instead of tape cover the thing in grease (multi-purpose or vaseline) - this stops it from overheating and protects the card from the damp....
 
Hello

The bottom two settings on the fan in my Micra haven't been working since I bought it so I decided to get a replacement resistor card. This arrived today and I've fitted it... however, the fan now only works on settings 1, 3 and 4 (an improvement from just 3 and 4 but not what I was hoping for!). Could this be a problem with something else in the car or do you think I've just bought a faulty card?

Thanks
Dom
 
Blower Resistor Card Repair

I know this post is old but, I am/was having the same issue. I took the card out and went to the local junkyard and bought a used/unchecked card. The guy said it was a risk as they hadn't tested it. It didn't work. So, none the less... I went to my local electric store and bought a variable temp solder iron(200c-450c), a stand, some little cleaning tools(came in VERY handy) and I bought some 2ohm and 3ohm resistors. I did the math and thought the resistors were going to be the fix. Wrong answer! It smoked the 2ohm resistor as soon as I turned on the fan. So, I saw this post and decided to give it a shot and IT WORKS perfectly. I actually fixed the bad card that I bought from the junk yard too. I have pics if it would be helpful to anyone. Not that fancy but it was/is my first electric(solder) board repair. LOL. Thanks for the tips, the nissan dealer wanted 62 Euro(that is roughly 100 dollars for me) and I just couldn't do it... I can't believe that this is such a big issue with a lot of people. I also believe you should check you blower motors and make sure that they are NOT pulling to many amps! I watched a video on youtube and they said that most fans should not pull more than 14.5 amps if is pulling 18 or more... time for a NEW fan or bearings or something.. Just my .02! I will upload the pics with this post(NO I WON'T, they have been disabled for me - :-()... hope it helps someone out! Oh yeah.. remember to keep your solder low to the board as there is just a small slit for the card to slide into behind the blower. I knocked off the first repair and had to do it over... just an FYI.
 
Hello Guys (from Portugal)..
I have the same problem in my super S , but i dont find the photos.
I search in forum and i dont found.
Do you have photos?

Thanks!!!
 
hey wNasc, try at your Portugeese forums, or straight in google.graphics. This is common issue, I find fix with photos at mine forums in my language too.

btw. in my case soldering won't work. The cooper layer is stripped off, it wont stick on it...
 
Matiz said:
hey wNasc, try at your Portugeese forums, or straight in google.graphics. This is common issue, I find fix with photos at mine forums in my language too.

btw. in my case soldering won't work. The cooper layer is stripped off, it wont stick on it...
Click to expand...
Hi Matiz, thanks for your tip. I follow micra portuguese forum, but the comunity is very low. UK forum have more people. i know the part , but i dont know the location. tomorrow i will try alone.. thanks again
 
Its just under the glove box on the left, no need to take glove box out, just remove that plug, un-do those silver screws and it will pop out!
13054536_10153649754242635_903239572_o.jpg
13009868_10153649754297635_2087161118_o.jpg
13010062_10153649754352635_1694334499_o.jpg
 
It's in the passenger foot well, up on the left hand side, two 10mm bolts iirc. Undo, and just pull out.
I always take them out every time I go to the scrap yard.
 
Where could I find one of these resistor cards? As my 2000 K11 Micra isn't blowing air effecintly through the passenger air vent , drivers side air vent and the at the windscreen.

Thanks,
Alex.
 
xTH3xMoDsZx said:
Where could I find one of these resistor cards? As my 2000 K11 Micra isn't blowing air effecintly through the passenger air vent , drivers side air vent and the at the windscreen.

Thanks,
Alex.
Click to expand...
When you say not efficiently, do you mean only blowing on 4 or not coming out of the vents properly (?)
If it is only blowing on 4 that is a common problem, go scrappers for a working one.
If all positions are working, then it is your cabin filter that needs changing, go to the search bar to find the fix buddy.
 
davyboy said:
When you say not efficiently, do you mean only blowing on 4 or not coming out of the vents properly (?)
If it is only blowing on 4 that is a common problem, go scrappers for a working one.
If all positions are working, then it is your cabin filter that needs changing, go to the search bar to find the fix buddy.
Click to expand...

Thanks for your reply.

Yeah, when I was trying to demist my windscreen I had it on 4 and it usually clears well, but I've noticed it hasn't been performing as well as it should.

So I should replace my cabin filter? Where is that located please?

Many thanks,
Alex.
 
Albert said:
Hi

Replaced my blower resistor a couple of days ago.But it has failed again.Any ideas on what the fault could be?

Thanks
Click to expand...

Check the pollen filter as if blocked it will restrict airflow and therefore the cooling of the resistor card which then overheats? Also check very carefully the resistor card male and female plug-in electrical connections are not loose oxidised or burnt?
 
I got a new card on ebay about 2 years ago (£8) as only low and high working. It was working last winter on all speeds but now (october 23) im back to only nothing and high. These cards obviously have a design fault. Will get the card out and solder resistors accross it, bypassing the card.
Having looked at the card (see photo) its overheating and burnt a track off the circuit board. So rather than pay another £10 for a card that will fail i am going to wire in 3 resistors, the value is about 2 ohms, high wattage to take the high current. Im going to solder resistors across the pins of the old card. The 3 resistors just step the voltage down from 12v (high) to 8v or 4v. Lower voltage lower fan speed. Will try make it flat enough to go in the same slot.
With the card removed i still get heater working on high.
Will post my results when i get around to doing it.
 

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