Fan has a mind of its own.

[EnyChevyUK]

I have a 88 K5 Blazer. The fan only blows on the highest setting, the hot/cold air works but when I want to demist or alter the direction of air flow 'vent', 'bi-level' ' etc nothing happens.I can hear something behind the dash moving when I switch to alter the direction of air but it doesn't alter the airflow to the selected vent.
Any help is appreciated before I get my tools. (I had a 78 Seville with the same problem, so is this a common GM fault ??????)

[Black95Blazer]

The speed issue is most likely a bad blower motor resistor, you can pick that up at any local auto parts store. The vent control is another issue that I have not been able to figure out on my fathers chevy pickup so I do not have the best or knowlage ot that yet, unless its opperated on a vacume then you may have a bad vacume line somewhere.

hope this helps a little
EK

[4x4x4doors]

The vent "door" that should move to redirect flow is either above the transmission hump upstream (airflow wise) of the floor vents or else between the glove box and floor (passenger side US models -- don't know if mirror image on the UK model). You should be able to observe them moving (or not) when you switch the controls.

[EnyChevyUK]

Thanks, I'll check all the vents and hoses behind the dash.
The Blazer is a US Spec (LHD) vehicle as they have never been 'officially imported' into the UK.Mine arrived in 1998. So the ''Bad Blower'' will only be available from a specialist supplier or via Ebay (USA) or other parts suppliers in the US who ship to the UK.
Most people over here who own 'US Vehicles consider it a hobby so tend to use them as a second car. (due to fuel costs). I however use mine most days aswell as a 99 Dodge Ram.
In a certain respect, most US car owners in the UK will be like the American enthusiasts who have MG's and other old British cars.

[4x4x4doors]

GM is famous (or infamous, depending on your point of view) for making maximum use of parts interchangeability. If there is a GM built something else (car, van or truck) available there, you may have a pretty good chance of finding an interchangeable part on something like blower motors. It can't hurt to ask.