General Fan resistor

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General Fan resistor

TTR

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Eh up all,

Daughters 500 1.2 cooling fan is not cutting in, dismantled resistor and its in bits ,,,(n)

I’m guessing I cannot fix it by simply soldering wires back on .:Df so anyone got an idea if there is a right way or wrong.

Are the ones of flea bay any good . Seen on at £16.00

Anyone got a good second hand one that’s any good Type Cast Boy (y)

Otherwise eba6 here I come and hopefully th3 fan is ok once I install it

Any help appreciated

Cheers all
 
If you leave it running long enough does fan start at high speed?

You could joint the two wires that connect to register and when it switches on it will run at high speed instead of low speed.
 
Any cheap eBay one should do the job, just make sure all the wire going to and from it are ok and do not show any signs of over heating and melting the insulation.
 
Eh up all,

Resistor is FUBAR (n), I’m no electrician, in fact I hate elecs:bang:

The coil part wound round the plastic tube is completed disconnected from the main plastic part.

If I knew which wire went to the two connectors on the coil I could re solder but no idea which way round the terminals would go - is there a right or wrong way round ?

Also would be guessing that one goes on to what looks like a small resistor and then to a connection on the coil, the other I’m guessing goes to another point on the main plastic part - am I making any sense :cry::cry:::D

It’s just going to be easier ordering a new part me thinks

Owt with nuts n bolts or bodywork I love - switch off when it comes to bl88dy electrical bits - makes no sense to me yet appears so simple to check stuff if you know what you are doing(y)

Thanks all - any inputs all welcome before this little car boils itself in this weather when stood in traffic
 
Eh up AGAIN!

Just thinking again:eek:

Is the little rad fan only activated by this resistor - are there any other methods by which the fan should switch on ?

I know the resistor is gone but trying to figure out why the fan won’t come on when the engine is running hot ie in the top quadrant on the dash display.

Am I understanding how the system works - if the engine temp sensor is working correctly, which I assume it is as the display works then what triggers the fan to work .?

Is it purely this little resistor and there is no other sensor that would signal it to work. - just seems odd it reliant on such a fragile looking part:eek:

If it’s something else as well that triggers the fan anyone any tips on what and where ,

Thanks for all the response so far - want to make sure I crack this for daughter can’t have the car ove4 heating these little engines are good but do suffer if cooling becomes an issue
 
Eh up AGAIN!

Just thinking again:eek:

Is the little rad fan only activated by this resistor - are there any other methods by which the fan should switch on ?

I know the resistor is gone but trying to figure out why the fan won’t come on when the engine is running hot ie in the top quadrant on the dash display.

Am I understanding how the system works - if the engine temp sensor is working correctly, which I assume it is as the display works then what triggers the fan to work .?

Is it purely this little resistor and there is no other sensor that would signal it to work. - just seems odd it reliant on such a fragile looking part:eek:

If it’s something else as well that triggers the fan anyone any tips on what and where ,

Thanks for all the response so far - want to make sure I crack this for daughter can’t have the car ove4 heating these little engines are good but do suffer if cooling becomes an issue

Usually if there is a fan radiator the cooling fan runs at 2 speeds . The current goes through resistor to motor for slow speed . For high speed the current goes directly to fan motor.

If you just have two wires on fan radiator join them together and that bypasses resistor so fab will run at high speed in stead of low speed.
 
It is the engine ecu that turns the fan on at low speed then if needed high speed, via relays and fuses.

The fan high speed may not start until engine gets very hot.

Well worth checking fan fuses

Plus check fan motor hasn't seized , that would blow fuses and possibly burn out resistor
 
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Mmmm

Checked in fuse box at the two fuses F6 and F7 and they are both fine, also fan spins freely.

Also connections at temp sender to engine block are both fine, no reason to believe temp sender is faulty

Will wait until New resistor arrives fit and see what happens, I’m guessing no way I can test it simply as a) no idea on electrics b) not got access to MES .

Typically when will the fan cut in at roughly what temp range as displayed on the digital dash - over half .?

Cheers for the advice all - working my way through it .

(y)
 
:eek:Typecastboy

Cracking mate - will try that. So that I’m cleAr, run car up to temp, put air
Con on and fan should cut in straight away ?

Fan turns freely so assuming it’s ok, might try and run a couple of wires just to check - watch me blow the bl88dy car electrics up !:eek:

That will be my next post .

I love this little 500 I got my daughter but he’ll fire :doh::doh: my wife’s panda cross is no problem in comparison (y)

Cheers all will no doubt be back with an update
 
Just to clarify there is another fan resistor built into the shroud of the radiator fan, this is what typecastboy is referring to, the interior cabin fan resistor has nothing to do with this, so you will need another resistor for the engine fan
 
Just to clarify there is another fan resistor built into the shroud of the radiator fan, this is what typecastboy is referring to, the interior cabin fan resistor has nothing to do with this, so you will need another resistor for the engine fan



Yes, I’m referring to the one in the fan housing. If the A/C is on with the engine running normal temperature the. The fan should periodically cut in for a few seconds.
 
All,

Yup just to be clear I’m referring to the resistor one located on the right hand side of the fan shroud held on by 1 8mm bolt.

That’s the one that’s fubar

W
Have ordered one today and will fit and test as per above.

It’s nowt to do with the interior fan but can appreciate how it could be confused - thanks should hav3 made it clearer.

Least it’s ruled one thing out then hopefully fan will work if not “I’ll be back”

Cheers for everyone’s inputs
 
Ok, I'm on the "last laps" with this on my boy's 2012 Punto 1.4 8 valve "Easy". Quite some time ago (couple of years maybe) his air con stopped working. He doesn't tend to run it regularly so I guessed probably the refrigerant had just leaked away (from what I know you need to run the air con regularly, even in winter, to keep the compressor seals lubricated and supple - I run mine for at least a half hour every two weeks at a minimum, but usually more often). He decided to just live without it due to the cost of checking and re-gassing as he couldn't afford any additional repairs found.

Then I had the car for a day for some maintenance on the brakes and I left the engine running for a while after test driving. I was tidying up tools on the ground in front of the car and realized the cooling fan wasn't running. The engine was fully hot after the drive and it had been idling for maybe 4 or 5 minutes. As I opened the bonnet to have a look it suddenly fired up at max speed (I know the air con cars have a two speed fan and it's very quiet at slow speed but this was definitely not running at slow speed. I hooked up my MES and tried driving slow and fast speeds. Only fast worked. Ok, most likely the resistor pack or associated wiring/connectors. As the resistor is easy to remove (just one screw) I whipped it out to be greeted by a nasty corroded mess. Worth mentioning though that this resistor only supplies current when the ECU selects slow speed for the fan. The fast speed should still be activated - albeit at higher coolant temp, but before boiling. So your engine should be safe from overheating even if this resistor pack is blown. Assuming that everything else, like, for instance the temp sensor, is working correctly.

Luckily the terminals (2 wire type plug on this one) were fine so I bridged them with a paper clip and tried with MES again. This time it ran fast on both settings. I bought a cheap replacement resistor pack on ebay but then we were locked down so I haven't been able to fit it yet.

So even if the resistor pack is blown/corroded the fast speed should still work when the engine gets really very hot. If it doesn't then the sensor, maybe a thermocouple these days? may be defective or again connectors or wiring. I've also been told that the fan should come on when the air con is selected so I'm wondering if his air con is going to "miraculously" work again once I've replaced the resistor pack?

As mentioned above this is a completely different resistor to the one that gives you the slower speeds on the interior heater fan. Several suppliers I contacted were confused and tried to sell me the interior heater fan resistor - beware, it won't work with the Rad fan!

Good luck, at least it's nice weather for working on cars outside!
Jock
 
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In MES you can turn on high and low speed fans to test this without the need to run the car for extended periods.

Aircon should still work even if the fan is disconnected as the car is not clever enough to know the fan is not working.

The reason for the fan is to cool the gas after it has been compressed as it passes through the condenser. In motion the movement of the air through the condenser is sufficient to cool the gas the high speed fan however keeps the gas cool when stationary.

Even if you don’t have the fan and you don’t cool the gas you would still expect the aircon to work normally in motion, and when stationary you would find the cooling effect in the cabin would tail off to a kinda tepid temp slightly cooler than outside air, but probably damp as it starts to blow the moisture off the evaporator.

So In this instance jock I don’t think your sons aircon will spring back to life.

The reason these resistors get so corroded is that (my theory) cars rarely need the fan these days especially with stop start so the engine isn’t running in traffic therefore the resistor is never used, never warmed up on a wet day to burn off moisture and so just rusts and falls apart
 
In MES you can turn on high and low speed fans to test this without the need to run the car for extended periods.

Aircon should still work even if the fan is disconnected as the car is not clever enough to know the fan is not working.

So In this instance jock I don’t think your sons aircon will spring back to life.

The reason these resistors get so corroded is that (my theory) cars rarely need the fan these days especially with stop start so the engine isn’t running in traffic therefore the resistor is never used, never warmed up on a wet day to burn off moisture and so just rusts and falls apart

Ah well, that puts paid to that hope! It was just something I read elsewhere that raised the hope. Looks like he'll not be worried about it though - tells me he couldn't care less if it works or not.

On his one the green material around the resistor was cracked in places but the coil still had continuity. The corrosion had formed wherever there is a connection - so where the resistor joins are. I considered resoldering but when I had a good look decided it wasn't worth trying.

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P1080789.JPG
 
Eh up all,

Firstly aaarrrgggghhhh :bang:

Fitted new resistor and started car at idle, temp at half way on the display, hit the air con on. Waited ......waited.........:cry: waited .....:nono: nothing !!!

No fan cut in at all, temp got to 3/4 and I then gave up drove it at around to cool it down and then shut off.

I need help.:mad:

I’m planning as follows, despite the fan appears to turn will take it out and try and connect 12v to it from a spare battery to check it works - Anyone done this and can tell me how easy it is . Where are the connections I can see a multi plug on the right below the resistor is this it .? Does it matter which pin ( assume it’s positive and negative ) you connect to.

Next plan - no idea really - checked fuses and they seem fine, is there a relay at all that governs this fan ?

The engine temp sender I’m assuming works as get the digital read on the dash, could it be faulty.? If so how and how could it effect the fan.

Welcome any more thoughts on this it’s driving me to distraction

Cheers all.
 
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Fan will always come on if you put the a/c on. It’s almost always the resistor that’s is faulty. It’s open to the air so no doubt gets corroded. You can run wires from the fan plug to the battery to test it’s freely running.

Typecastboy- any step by step you can give me on doing the power to the fan plug even a brief explanation would help me.

Cheers in advance
 
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