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Heater not working? Read here!!

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Once again, the colder days are closing in on us, and I see an increase of threads like "Heaters", "Blowers", "Internal Fans not working"
This topic keeps rearing its head every year about this time, so I thought a guide on how to fix this should be written.

So, if your heaters are not working, then read on. Does your blower only work on its highest setting? read on.

Firstly, you need to find out which heater system you have. Ph1 (mainly before 1994) have heaters with 3 speed settings, and ph2 (post 1994) have 4 settings.

Pre 1994


Post 1994


This is important, as the 2 variations require a different resistor pack.
"Resistor pack ?" I hear you say. Yes, this is the part that has most probably died on you. The heater blower speed is controlled by reducing the amount of power going to the blower motor. At a full 12v, you get full speed. By passing the 12v through various resistors, less power getts to the motor and the blower fan turns slower. If the resistor pack stops working, all you have is the setting with the full 12v, where the power does not pass through the resistor pack. This is why, if your heater only works on full speed, be it 3 or 4, then your are most likely looking at a broken resistor pack.
Why do they break?" is your next question. Because Opel/Vauxhall made a bad design, and fitted the resistor pack somewhere damp and wet. The resistor pack doesn't like this. The connections start to corrode away first, then eventually the whole pack just rusts from the inside and the whole thing stops working.
This is a resistor pack.:


Top Tip: The resistor pack in other Vauxhalls/Opels differ from shape, and cant be fitted permanently eg, the Corsa B resistor pack can't be fitted into the Astra Mk3, but the electrical fittings ar the same, so if you only have one from a different car you can still test the system to make sure it is the resistor pack you need to change.

A new resistor pack looks like this:

Note the amount of pins. A 3 speed blower has 6 pins, and a 4 speed blower has 7 pins (as shown in the picture)

Now you know what has failed, and what it looks like. Where is it?
The resistor pack is found under the pollen filter, here:


You can access it without taking the windscreen wipers and scuttle panel off, but it is easier to replace it if you do take the wipers and scuttle panel off. Because the pins corrode so well, it can be difficult getting the plug off the resistor pack. Once you take off the pollen filter you will see it:

To remove it you should:
  • Remove the windscreen wipers
  • Remove the scuttle panel
  • Remove the pollen filter by releasing the 2 retaining clips
  • Undo the 2 retaining screws holding the resistor pack in place

Now fit the new resistor pack, and replace everything in reverse order. That should cure your heater problems.

Hope this helps you through the next winter :)

Jason

If you want this as a PDF, then click here:
www.madhaus.de/resistor.pdf
 
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Great write-up, Lefty! It's worth noting, though, that if your resistor pack is not really-really dead, you can get away without buying another one, by replacing the thermal fuse on it, as this is the first thing that goes when the thing gets wet for whatever reason. I've done a similar how-to on one of our forums - here's a picture of how I did it:

(sorry about the blah-blah in my native language :tape:) - the original (184 degrees) has failed, so I replaced it with another one, rated at 157. Hope this helps.
 
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Mine stopped working on 1 and 3, so only 2 and 4 worked, but now, none of them work at all.. Still looking at resistor pack? because you said that it will still work on full :confused:
 
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Working on full is a normal sign for resistor pack. If the heaters stop working alltogether then you should still look at the resistor pack, although it is odd for only 1 and 3 to stop working. But yes, still take a look at it mate.
 
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its a good idea to seal up your new one as well with some electrical insulation tape that should stop it from rusting and getting wet or giving it a lick with high viscosity grease should do around about the same job
 
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im going have a look at mine as it dont work on 1 but works ok on 2 and 3
 
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Hi guys,
I've got a 4-speed heater blower...........it has only been working on 3 and 4 speeds. I've just replaced the resistor and the blower is now working on all speeds again............thanks for posting this thread - really useful...........and for those of you who need to replace the resistor, it really is a pretty straight-forward process............the new genuine Vauxhall part resistor cost me £21 on ebay...........best regards.
 
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Does anyone know where to by on of these heater resisters for a mk3 R reg astra arctic? Just bought car and don't have settings 1-3 working but 4 does. Dad thinks it's switch or fuse.

Also, anyone know how to replace bulb behind switch console?
 
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Does anyone know where to by on of these heater resisters for a mk3 R reg astra arctic? Just bought car and don't have settings 1-3 working but 4 does. Dad thinks it's switch or fuse.

Also, anyone know how to replace bulb behind switch console?
Best place to try is your local breakers yard. I got mine for 3squid m8 also stuck a spare in my pocket jus incase. Make sure you dont get 1 thats all rusty tho cos it will not work.
 
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mines like dat also only blows out cold wots da problem
You Spoon !!

First of all, if you wrote english people might not get the impression your are some sort of retard, and secondy, if you can read english, the solution to your problem is very clearly explained in the above posts.

:doh:
 
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This is great guide, mines a different problem, it only blows out warm air even when cold is selected will replacing resistor pack solve this or is it something else? Cheers
 

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