Splicing Fan Wires

I spent some of the weekend in Shenzen at the SEG Market (crazy electronics market). Picked up some San Ace 120x38 2600 rpm fans for about $4 USD each!

Anyway, one of them came without a plug on the end, so, no problems, I have a spare plug with wires hanging out of it, stripped the wires at both ends, connected it up, and it works... but at about half the speed the others work at. So I figure my crappy wiring job is to blame. To splice some wires without losing power, whats the best way? I figure my options are:

1. Solder (need a soldering iron)
2. Pop the plug and re-crimp it (might need a crimping tool)
3. strip a longer section and do a better job twisting the bare wire together

#2 isn't really an option, given my long term plan is to wire all 3 fans to a single connector (so I better get some sleeving). I can imagine #3 will make it better, but probably not perfect? Admittedly I did a bit of a rush job, as I really only wanted to test the fan worked, as I don't have a use for the fans right now.

Any advice would be appreciated! Is #1 the best way to do it?

Thanks

Hmm, it's pretty straight forward splicing wires, just keep them color coded:

Red to Red
Yellow to Yellow
Black to Black

If the fan is running at 1/2 it's speed, then something is wrong with the fan itself.

Even splicing them (without solder) should not create the problem you're describing unless you undervolted them.

you should solder them, you can use a jet lighter.

otherwise try marettes. https://www.addison-electronique.com/catalog/images/produits/section-q/161084.jpg

if its running HALF spped you plugged it SERIAL. it need to be parrallel.

The wires are in the correct order, its not that I am wiring them incorrectly (at least as far as the colours go). I am almost certain its a poor splice... poor splices can introduce extra resistance and cause voltage drops.

Spawn: Thanks, I guess I should just stop trying to cut corners and do it properly. I'll pick up a soldering iron + solder tmr.

Thanks guys.


EDIT: Boulard83: Half was an estimate, not an absolute... and it was the only fan connected. Sorry I didn't make that clear.

Remember to get lead-based solder. It's not as environmentally friendly, but it's significantly easier to use. The RoHS stuff has a much higher melting point and is a royal pain to work with.

Just twisting the wires together will be enough to reduce the resistance to negligible. Especially for a low power fan. If it isn't spinning properly with the leads twisted together, it won't make a difference soldered. Would you have spliced the fan onto a 5v line? (I believe 12v on molex is the yellow wire, maybe check with a multimeter) Or perhaps the fan is rated for 24v instead of 12?

I only wrapped pretty short amounts of bare wire around each other... hence I thought that was to blame. I haven't got any solder yet, will do so later today when shops open.

I definitely have the wire colours matched (I may be a noob, but I'm not *that* bad! )... and I have 3 identical fans, and the points the wires are soldered to appear to be the same. Does a 2600rpm fan count as a low power fan? (12v 0.52A).

Once I get some solder, I'll report. Thanks for all the replies... hopefully its not an issue with the fan itself.

One thing, the wire attached to the connected is thinner than the wire from the fan. This shouldn't matter right?

Remember that the Yellow wire off the PSU is the 12V, not the Red. So you would connect the Red wire from the Fan to the Yellow on the PSU.

As for running at half speed, it sounds like you hooked to the Red on the PSU.

A bad splice job won't make a case fan run slow. It uses about .2 - .3 amps at 12 volts, even the crappiest connection should have it spinning fast. The fan is damaged. Not a problem of wiring it in "serial" as said above, or two fans would be spinning slowly. Re twist the wires and try it again, but I can guarantee that less than perfect wiring isn't going to stop about three watts of electricity or impede it.

hokiealumnus said:

Remember to get lead-based solder. It's not as environmentally friendly, but it's significantly easier to use. The RoHS stuff has a much higher melting point and is a royal pain to work with.

Click to expand...

+1 Not a fan of the new RoHS solder.. I don't think it adheres as well as the lead based rosen core.

Hmm, okay, maybe its a bad fan then (crap!). I still haven't gone to get some solder, going now. However, I did hook up the RPM (and ground) line to the mobo using a splitter from my fan controller, so I could check the RPM. A 'good' fan maxs out at 3600 RPM (wowsa), the 'bad' one at 1400. Numbers see a little too neat... but given I am getting the voltage from a fan controller, which, AFAIK, only supplies ground + 12v, I don't see how I can have the wrong voltage.

Could just be a fubar fan... which, for $4 bucks is annoying but not unexpected.

Thanks again!

(3600rpm!)

Ok just in case there was any doubt in anyone's mind, its definitely not a wiring problem.

Thanks for putting up with my stubborn hope it was the wiring!


Feel free to say "I told you so"