Trying to wire up an extension cable for PC components, some questions about how

Trying to wire up an extension cable for PC components, some questions about how
Posted by Cyber Akuma on 26 Mar, 2023 18:34
I am from the US, and I have a Dell system that has proprietary fan headers (Specifically the older Precision workstations if anyone is familiar with those), I am pretty sure I have figured out what headers they use for their fans and I want to create what are basically male-to-female extension cables except with an additional wire that will connect to other components (Basically just to carry the PWM signal to other fans) but I have never really crimped wires like this before or purchased specific parts like this so I have a few questions.

So, the fans have 4-pin and 5-pin headers which I am about 99% sure are these ones:

4-Pin: https://www.molex.com/molex/products/part-detail/crimp_housings/0050579404
5-Pin: https://www.molex.com/molex/products/part-detail/crimp_housings/0050579405

From my understanding, that is just the plastic piece itself and it doesn't even come with the crimp connectors in it, those I have to buy separately, they appear to be these: https://www.molex.com/molex/products/part-detail/crimp_terminals/0016021114

Thing is, I am not sure what the male counter-parts to those connectors are. The site does list what connectors those will mate with, but there are several categories and each one has a list of several parts, I am not sure which one I am supposed to be using.

Likewise, the male connectors also don't seem to have the crimp pins in them, apparently that's these: https://www.molex.com/molex/search/partSearch?pQuery=&sType=s&query=70021

But that's a list of several ones and I am not sure which ones I should be using.

I've seen ones that seem to have connectors already on them too, but they claim they are "2 circuits" which confuses me. This one for example has 4 pins, but claims "2 circuits": https://www.molex.com/molex/products/part-detail/ffc_fpc_connectors/0015388027

From my understanding the wire used is generally 24AWG wire, that should not really be too hard to find even in different colors.

How does one even crimp these specific connectors? I know I would need a tool for that (no idea what kind), can anyone recommend a budget tool for this or has ever crimped these types of connectors before?

If it helps, what I am trying to do is basically "break out" the PWM signal wire and connect it to a SATA adapter that will power additional fans while also passing on the PWM signal. The cable normally expects you to plug it into an motherboard header and has a PWM and PRM wire. I want to only connect PWM wire since I want just the PRM of the proprietary fans to be reported, something like this:

I would also need a male standard 4-pin PC fan connector for this, shouldn't be too hard to find, something like this: https://www.amazon.com/Maxmoral-Plastic-Computer-Interface-Connector/dp/B08HYTGH7D/

But does anyone know the actual name/model number of that connector so I can search around for it? (Also, any idea if these have to be crimped with a different tool than the molex connectors I listed?)

#1 Reply
Posted by MathWizard on 31 Mar, 2023 21:36
I can't see those links, but unless you really want to buy a crimping tool and go through the hassle of that, what about something like this, they come in 3 and 4 pin models, IDK about a 5pin fan.
https://www.amazon.ca/Electop-Chassis-Cooling-Molex-Controller/dp/B071KNT7FW/ref=sr_1_3?crid=2HXBLBCOI0GCO&keywords=molex+fan+breakout&qid=1680298293&sprefix=molex+fan+breakout%2Caps%2C86&sr=8-3

The only crimper I know is the Iwiss crimper I bought, it was under $80US iirc, and it's better than some budget ones, but IDK how good it really is, or in the long term.

If all you really want to do is jumper the PWM to a few other fans, I'd just find some solid-core copper wire, that fit tightly in the connector holes, and then I'd solder a couple of pieces of that onto the jumper wire, and then tape it once the wires are in place.

There's kits of connectors, with the little metal bits, and different plastic housings, IDR the names of it all tho.

#2 Reply
Posted by Cyber Akuma on 31 Mar, 2023 22:11
Quote from: MathWizard on 31 Mar, 2023 21:36
I can't see those links, but unless you really want to buy a crimping tool and go through the hassle of that, what about something like this, they come in 3 and 4 pin models, IDK about a 5pin fan.
https://www.amazon.ca/Electop-Chassis-Cooling-Molex-Controller/dp/B071KNT7FW/ref=sr_1_3?crid=2HXBLBCOI0GCO&keywords=molex+fan+breakout&qid=1680298293&sprefix=molex+fan+breakout%2Caps%2C86&sr=8-3

The problem is those kind of devices use a standard PC fan connector/pinout. The whole reason I am making custom cables is because the system uses a proprietary connector and proprietary pinout.... but the same standard 4 wires normal PC fans use, just pinned in a different order and with a different connector, so you can still connect standard fans by re-pinning the wires.

There's a lot of detail about it here: https://wiert.me/2021/10/28/dell-fans-use-a-different-pin-layout-than-normal-fans-so-watch-out-before-connecting-them/

After looking it over again, it seems very likely that the CPU fan is .75 Amps, which if assuming that the header has a standard max output of 1 Amps (Who knows with a proprietary system, but the other fan headers are definitely at least 1 Amp since they come with .95 Amp fans on each of them) I can connect one of the fans directly to that.

Basically, my current plan is to split the 5-pin CPU Fan header, with all (5? might as well populate the 5th wire too just to be safe) so one end has all 4/5 wires going to the stock fan, and the other end with just 3 wires (not including the RPM signal wire) going to a standard PC fan. Something like this:

And another splitter for the 4-pin fans that ONLY connects the PWM wire to the standard 4-pin Fan adapter, powering the FAN itself off SATA. Something like this:

Quote
The only crimper I know is the Iwiss crimper I bought, it was under $80US iirc, and it's better than some budget ones, but IDK how good it really is, or in the long term.

I saw this one being "frequently bought together" with the kind of connectors I was looking to use, any opinions on if this would work?

https://www.amazon.com/dp/B00OMM4YUY/