Heater blower

Last year my heater blower packed in on 1,2 and 3, but 4 was OK, so a chappie who worked in a Ford workshop gave me an old spare resistor thingie which when I swapped them over started up 1,2 and 3 again (as well as 4).

It lasted a year, then last week went pop again (1,2 and 3 off, 4 OK). So I bought one off Amazon (just ?8) for Ford Focus 2002 and in it went and all started again.

Yesterday, got in the car and 1,2 and 3 have gone pop again, but now also 4 has gone as well. Checked the 30amp fuse (changed it) no joy.

If I get another resistor and change it again, will this do you think, make all 4 work again? I'm thinking the resistor has lost the loop to all 4 settings maybe?

I know nowt about cars and mechanics so thought I would ask if anyone has an idea why all 4 have now stopped blowing and the likely reason & solution.


Cheers.

Bilbo.

I just checked a diagram which seems to suggest fuse 64 (10 amp) is responsible, but that sounds too low to me.

Also according to that diagram, when ignition is on, relay K79 should close which will always provide 12v to the fan motor. Earth is switched, speed 4 is a direct connection to earth, speeds 1-3 go via the resistor to control speed.

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Attachment 30826

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Originally Posted by Over Carl

I just checked a diagram which seems to suggest fuse 64 (10 amp) is responsible, but that sounds too low to me.

Also according to that diagram, when ignition is on, relay K79 should close which will always provide 12v to the fan motor. Earth is switched, speed 4 is a direct connection to earth, speeds 1-3 go via the resistor to control speed.

Password for rar sent via PM.

Attachment 30826

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Cheers fella, will have a look at that tomorrow.

Quote:

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Originally Posted by Over Carl

I just checked a diagram which seems to suggest fuse 64 (10 amp) is responsible, but that sounds too low to me.

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My handbook says the heater blower is on fuse 64 as you say, but it says it is 30 not 10. I looked and it is a 30 amp fuse, which I have swapped for a new one and that has made no difference....

This is why it's blowing dude!. I sneaked a photo of your windscreen. :D

https://s.aolcdn.com/hss/storage/mid...m_main.jpg.jpg

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Originally Posted by dpSparhawk

This is why it's blowing dude!. I sneaked a photo of your windscreen. :D

https://s.aolcdn.com/hss/storage/mid...m_main.jpg.jpg

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:teeth: :laugh:

:tosser2:


Actually... I've only got 3 Ian, but I have maybe 3 more on the way for reviewing soon, lmao....

All sorted - found a duff fuse after all.

Blowing like a good 'un again.

Cheers lads.

Bilbo.

It requires the air flow to cool the resistor, make sure your pollen filter has been changed recently.

Sent from my SM-G935F using Tapatalk

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Originally Posted by BIG-TED

It requires the air flow to cool the resistor, make sure your pollen filter has been changed recently.

Sent from my SM-G935F using Tapatalk

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Yes and the lower the setting(1)the hotter it gets with the least air flow, that's why they burn out.

Is this filter under the bonnet just below the plastic panelling beneath the windscreen wipers?

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Originally Posted by Bilbo_baggin

Is this filter under the bonnet just below the plastic panelling beneath the windscreen wipers?

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Yes that's the one.

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Originally Posted by riget

Yes that's the one.

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Cheers fella.

I can get one for a tenner. :)

what goes on the resistor pack is a thermal fuse which is strapped across the top of the pack
what i think causes the thermal fuse to go in the first place is the motor bushes wearing causing the motor to draw more current to do the same job which in turn pushes more current through the resistor pack causing more heat

my mate has just changed the heater motor on a focus for the same reason he went through 3 resistor packs before the motor itself decided to pack in

it's a pretty common fault on fords