So the blower was only working on settings 3 & 4 and I'd read up how this was common etc. I sourced a replacement BMR thru ebay which seems to be a genuine chrysler part and just fitted it. Pretty easy job which is just as well as now the blower only works on setting #4. It's seated all OK and screwed/clipped in placed.
Before I start moaning to the vendor, is there anything else that could case this problem - the fact that the problem is difefernt (though worse!) now suggest it was the BMR all along doesn't it?
T (in the UK)