Optiplex 790 fan chaining

[UniNart]

So I have an optiplex motherboard with only one 5 pin (4 wire) header and I’m trying to add another fan in its new case but I am uncertain on what wire is which on the new fan to splice them? Would this trigger an error on startup even if done properly?

[fordy_rounds]

Did some searching, found this dell forum post. In summary, it looks like they're using standard colors in a non-standard order. So as long as you splice new ground to Dell black, and new 12V to Dell red (leave the new sense un-spliced; since it's a signal from the fan, it's best to only have one signal going to the MB), you should be ok. Note that the new fan, based on its 3-pin connector is not PWM, so it'll just run at constant (full) speed. If done properly, it shouldn't produce any error, as all you'll be doing is drawing a little more power.

[UniNart]

Thanks I’ll try that