Heater Blower Problems - HELP!

For reasons best known to itself, my heater blower decided to only work on full blast today. It has been working no problem at all. Went to drive the car today, no fan! Turned it up, and it finally came alive on setting IIII (full blast). The aircon is working 100%. Nothing has been done to the car, parked it working, restarted it later and it was dead on setting I, II and III.

So far I have fiddled with the connections on the back of the fan speed selector switch. I have checked, and replaced the 'Fan Blower' fuse inside the main fuse box... still nothing on I, II, or III - You know I need to get this working properly before the hot weather gets here :)

Any help, tips, advice, ideas, diagrams, links, anacdotes or assistance greatly appreciated.

300 Essie
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300 Essie
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I don't like replying to my own posts, but I have been told that this may be due to a faulty heater blower resistor pack. Does anyone know what this 'thing' looks like or where it's situated on a late W126 300 SE (petrol straight 6)?

There's a box in the engine bay that could be it, it has four coils of stout wire inside and the outside is covered in plenty of vent holes. The loom attaches via a plug, the loom wires that are on the plug are all green (with different colour traces). Standing in front of the grill looking into the engine bay facing the windscreen, the box is mounted on the left hand side inner wing, at the same sort of height as the exhaust manifold.

Does any of this ring any bells with anyone out there? Is this the mystery heater blower resistor pack, or am I barking up the wrong tree?

300 Essie
Reply to
300 Essie

You mean the blower that blows air inside the car? It is located under the passenger side dash (footwell area and look straight up at the dash)... you have to take out the front under cover... then there is a black cover for the blower motor... and then another cover to drop the whole motor assembly.... now then you can get the motor out with the blower fins.

The resistor pack is on the opposite side of the fins... you can see it on the side... graphite thing that touches teh center motor core. Easy way to repair this is put in a new motor. That way is however $153 way... you note the amount of shaft sticking out of the blower wheel because you will have to install it the same distance on the new motor.

Resistor pack is cheaper but you have to find someone who can sell it to you... any electric motor repair shop can do it for you.

Reply to
Tiger

Thank you for the advice and instructions, I have to get this fixed over the next couple of days and this info will be invaluable. All and any tips are greatly recieved.

Thanks again

300 Essie
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300 Essie

Very easy job... I pretty much detailed everything you need to know

Reply to
Tiger

Dropped the passanger side under-dash, I could see the blower motor and fins but no resistor pack!!! I could see the thick green and brown wires that feed the motor, but they disappeared up into the loom and off towards the bulkhead.

So, I acted on my previous hunch and removed the box that is inside the engine bay. It was badly corroded inside and inside the multiplug. I stripped it down and one of the resistor springs was loose..... ummmm... just what I was praying for! After bodging it back together the fan now works properly on all settings and I have a part number to get a replacement from my dealer :)

Thank you all for your help and ideas.

300 Essie
Reply to
300 Essie

Mmm... so tell me... where exactly is that box you are talking about? I'd like to know about this stuff myself...

Reply to
Tiger

OK - best way to describe it... it is a small sheet metal box 2"x2"x3" in size. It is covered in ½" holes (I assume to help cool these big resistors). It is on the drivers side (RHD) inner wing inside the engine bay, just next to the radiator expansion tank. It is held in place by two 8mm bolts that are held in place with nuts that are accessed from under the right hand side wheel arch. There is a multiplug that attaches to the box with green wires (with different trace colours).

Maybe once I have a new one in place I could whack a picture of it up somewhere?

300 Essie
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300 Essie

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