I have a iMac 9,1 and replaced my hard drive with a 1 TB Samsung SSD. I bought the upgrade kit from OWC but the inline thermal sensor they supplied does not fit on my machine. I reinstalled the original sensor but the fan runs constantly at high speed (5800 rpm)
Any suggestions? OWC tells me there is no 3rd party sensor that works with my machine
Hmm, an iMac 9,1 is the Early 2009 model. It should be quite similar to my Mid 2007 internally. I put in an OCZ Agility 3 back in 2013, used the stock SATA cables and the stock temperature sensor since it isn't inline on this model, rather an external sensor. I made sure it was taped down well like it was on the original HDD, made sure it was plugged in securely and it's been great. I did mount the 2.5" SSD with double sided tape though
You might try downloading a temperature sensor app, like iStat, and see if it shows the HDD temp. That might tell you if it came unplugged during reassembly, or if it's damaged. It should show up at a reasonable temperature if it's working.
I have heard that there is a software workaround but have not tried it myself, but I guess using that one can set the fan speed at a constant level could be worth checking out
Leon
I know of smcFanControl, but it only sets the minimum RPM, so it won't cook itself when it heats up. It's to keep it cooler at idle or on your lap such as the case when watching flash videos on a MacBook. You can set it up around the 3,000-4,000 RPM range to keep it cooler. But it will ramp up beyond that if needed. So you can't really limit the fan speed.