[SOLVED] Pump runs at 1% power until it is unplugged/plugged back in

Mar 7, 2022
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I have a 12V ddc pump. It has a pwm header and a molex connector. No matter how I connect it (motherboard+molex) or even just molex I get the same issue.

When I first boot my computer the pump runs at about 70 rpm, not enough to do anything. When I unplug and replug the molex connector while the PC is on the pump will come to full power as expected. As soon as I turn the computer off, I can expect to get the same issue every time I boot it back up, always comes on at 70 rpm and wont function properly until it is unplugged/re plugged again.
 
Solution
I have a 12V ddc pump. It has a pwm header and a molex connector. No matter how I connect it (motherboard+molex) or even just molex I get the same issue.

When I first boot my computer the pump runs at about 70 rpm, not enough to do anything. When I unplug and replug the molex connector while the PC is on the pump will come to full power as expected. As soon as I turn the computer off, I can expect to get the same issue every time I boot it back up, always comes on at 70 rpm and wont function properly until it is unplugged/re plugged again.
When you connect to Molex, pump/fan/motor has no way to report RPM or adjust RPM. You should never but never connect both Molex and MB header at same time, MB header at least might burn...
I have a 12V ddc pump. It has a pwm header and a molex connector. No matter how I connect it (motherboard+molex) or even just molex I get the same issue.

When I first boot my computer the pump runs at about 70 rpm, not enough to do anything. When I unplug and replug the molex connector while the PC is on the pump will come to full power as expected. As soon as I turn the computer off, I can expect to get the same issue every time I boot it back up, always comes on at 70 rpm and wont function properly until it is unplugged/re plugged again.
Sounds like the psu has a fault in the molex line or isnt strong enough
 
I have a 12V ddc pump. It has a pwm header and a molex connector. No matter how I connect it (motherboard+molex) or even just molex I get the same issue.

When I first boot my computer the pump runs at about 70 rpm, not enough to do anything. When I unplug and replug the molex connector while the PC is on the pump will come to full power as expected. As soon as I turn the computer off, I can expect to get the same issue every time I boot it back up, always comes on at 70 rpm and wont function properly until it is unplugged/re plugged again.
When you connect to Molex, pump/fan/motor has no way to report RPM or adjust RPM. You should never but never connect both Molex and MB header at same time, MB header at least might burn.
What PWM or 3 pin MB header are you connecting it to ? Most new MBs have an Water_PUMP header and /or AIO_Pump header . First one is usually adjustable and second one runs all the time 100%
Water_PUMP headers can usually handle at least twice the power of AIO or case fab headers.
 
Solution
Mar 7, 2022
4
1
10
When you connect to Molex, pump/fan/motor has no way to report RPM or adjust RPM. You should never but never connect both Molex and MB header at same time, MB header at least might burn.
What PWM or 3 pin MB header are you connecting it to ? Most new MBs have an Water_PUMP header and /or AIO_Pump header . First one is usually adjustable and second one runs all the time 100%
Water_PUMP headers can usually handle at least twice the power of AIO or case fab headers.
When I have it connected to the motherboard I have it connected to a sys pump connection so I don't think there is any problems there. I can get the pwm curve to work when plugged into the mother board or I can get it to run 100% when molex only, however, both cases require me to plug and unplug it to actually get it to work everytime the computer is booted
 
Thats what I thought at first, bought a whole new PSU, and 1000w so I'm reasonably certain it has nothing to do with the PSU
Then it sounds like there is a short drawing the extra power somewhere else. And you may need to rewire it if it's a serviceable pump. If not then replace it this normally is do to a wire not fully connecting and touching something else drawing the current unplugging and replugging resets the current to the pump
 
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Mar 7, 2022
4
1
10
Then it sounds like there is a short drawing the extra power somewhere else. And you may need to rewire it if it's a serviceable pump. If not then replace it this normally is do to a wire not fully connecting and touching something else drawing the current unplugging and replugging resets the current to the pump

Very interesting thought, that sounds rather reasonable. There is indeed a lot of circuitry in a pump like the one I have so I wouldn't be surprised if there was a soldering issues causing a short or something. Thanks for that information!!
 
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