Question ThermalRight all-in-one cooling needs 2 connections, i only have 1

[luv2liv]

i got this Thermalright Aqua Elite 120 V3.
it needs two 4pins connections, one for the fan and another for the pump.
sadly my mb only has 1 CPU Fan connection. anyway for me to get a 2nd connection to power up the pump?
on the mb of my HP EliteDesk 800 G3 SFF... i see empty connections for HLCK (5pins), USB C (5pins), SD READER (11pins), COMA (13 pins), and PS2/COMB (19pins). plenty of USB ports in the back. can i use any of those to power up the pump's 4pins?

 

[MangoX]

I would use a molex to 4pin fan adapter if you can find one. Or disconnect a chassis fan and use that.

 

[Paperdoc]

It's even simpler because this system has only ONE rad fan. the limiting factor is that the mobo CPU_FAN header has a max current output of 1.0 A. The specs of the AIO system say the PUMP uses max 0.4 A, and the single rad fan uses max 0.2 A. Total max is 0.6 A, well below the max of the header, so you can connect BOTH devices to that header and not risk overloading it.

To do that you need a simple SPLITTER and should connect it in a particular way. But be wary of how these things are labelled by sellers. They tend to use the terms Splitter and Hub as if they are the same, and they are NOT. A SPLITTER is a simple device with one "arm" going to a mobo fan header and two or more output "arms" for plugging in fans or a pump. An example

https://www.amazon.com/Rosewill-Splitter-Duplicator-Converter-Adapter/dp/B01N0XQ7XC?crid=2IN77RR5XVE59&dib=eyJ2IjoiMSJ9.i9HK7YRAElgyB-3_c5aueuOKsBXo_-rM47MCos0XJ2xMArPPe_Dn2am2Y1UnSlOoh8arX3IVcvDcU_BP0snZq6KfiAaB7patw9W_yn1OT8TebO7TYgz7LvPF5wc7g9fFt2Nt3hxbP4mrPpol4WAumDZtS4s5P1V0FLhZAxU_RWp9T1b0Ig4VyvwlxUVM19_7HNqXRjBNhc5OFthINGmRrh_cR3qs-SMxy65wwFW5JQE.Ofzwp3aYpenDx1DQNCHs8gu0CxnfC-cpGILweiTZ4OI&dib_tag=se&keywords=fan%2Bsplitter%2B4%2Bpin&qid=1769799524&sprefix=fan%2Bsplitter%2Caps%2C184&sr=8-2&th=1

That has two outputs for 4-pin fans.

A HUB has those same, BUT also has a third "arm" or edge connector that connects to a power output from the PSU directly (either a 4-pin Molex or a 15-pin SATA power output. You do NOT need one of these.

Now the connection detail, and first the why. All fans send a speed signal (a series of pulses) back to the host header on Pin #3. Any fan header can deal with the speed signal from only ONE fan, so any Splitter or Hub will send back to its host header the speed of only ONE of its output devices and will ignore all other speed signals. On a simple Splitter like linked above, only one of its output arms will have all 4 pins in it, and the rest will be missing Pin #3 so those devices cannot send back a speed. The CPU_FAN header pays special attention to the speed signal it gets to detect NO speed, indicating FAILURE of that cooling device for the CPU. If that happens it takes quick actions to protect the CPU from damage due to NO cooling, often shutting things down completely. When using an AIO system the particular device whose operation is critical is the PUMP - no water flow means NO cooling. So you MUST connect the power cable from the PUMP to the only Splitter output arm that HAS all 4 pins.That way any pump failure WILL be detected right away and the protection system activated. The speed of the RAD FAN will NOT be "seen" anywhere and cannot be monitored automatically. However, if that fails the rise of internal temperature inside the CPU chip will be much slower and that WILL be detected by another monitoring system that takes different actions to protect the CPU chip.

 

[BoomerD]

What motherboard? You SHOULD have a pump header if the board is fairly recent.