How to connect iMac temperature sensor on a WD Blue 1 TB?

I have my friends iMac in which he needs a new drive. He got a WD Blue 1TB HD to install. I am trying to help him with it, but the first problem has popped up. Mac uses a temperature sensor on its HD's & I don't know where to plug it into the WD Blue. There is an 8-pin connector next to the SATA , but which of the 4-pin combos do i plug it into?

Any suggestions or help anyone can give me would be greatly appreciated.
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andyalderConnect With a Mentor Commented:
I didn't realise iMACs had custom drives with separate temperature sensor connectors either but there you go, proves I don't know iMACs.

I know how to google though, should sort the problem better than shorting the pins out. There's a video on fitting it to the drive as well, the interesting bit starts about 4 minutes in where they start to add the custom sensor to the disk case.
We need to know which model iMac. Alternatively look at the repair guide here for the appropriate model:
Dr. KlahnPrincipal Software EngineerCommented:
The 8-pin connector on hard drives is generally reserved for factory testing, with the possible exception of a 6/3 Mbps slowdown jumper.

I've never seen a hard drive with a temperature sensor; since about 1999 there has no need for such.  All SMART compliant drives return their temperature as one of the functions.

SMART temperature reading
If there is a temperature sensor it definitely does not plug into the drive.
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BlinkrAuthor Commented:
Thanks for the quick response!

Thanks Strung I will be checking out that site.

Dr. Klahn, that is a PC Windows window displaying there, isn't it? My question was about an iMac. Checkout Seagate drives. There is a 4-pin connector next to the SATA connector. That is where the iMac temperature sensor plugs in.

andyalder, this isn't a custom drive situation here. The Seagate drives have the 4-pin connector for the iMac temperature sensor next to the SATA connector. I saw the OWC connector on several of's  videos. I just got one at Amazon.

Now to everyone: I already have a WD Blue drive to use on this upgrade. That's why I'm not buying a Seagate drive. I was checking to see if anyone knew how to connect the temperature sensor to the WD.
andyalderConnect With a Mentor Commented:
Sorry, my bad it's a generic drive not customised.

It's the Seagate diagnostic serial port that the apple temperature cable is connected to. WD diagnostic port is not only a different connector it also has a different command language
BlinkrAuthor Commented:
I did use Google & found several videos. The OWC video showed how to install a new drive but it didn't say anything about purchasing the replacement thermostat that you stick on the drive. It just told you to stick it on & connect it. It took a little more research to find that.

But thanks for posting the link. BTW there are 2 videos. There's an old one & then they did an updated video.

Thanks again!
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