Jens_l Posted June 26 Report Share Posted June 26 Hello Today i am using a standard relay to turn on my stock Volvo 940 electrical radiator fan. But i wanna run the fan with variable speeds so after some googling i have found that people har using "dorman 902-310" to run their fans at variable speeds. The Volvo fan draws about 23-24A at full speed and the dorman is rated for 40A What settings should i use in Link and do i use GP PWM output?. And can i also get it to raise the fan speed if the IAT is getting high. And can also have non driven speed lockout Megasquirt users seems to run it at 250hz. And will wire it like the picture below. Quote Link to comment Share on other sites More sharing options...
Adamw Posted June 26 Report Share Posted June 26 The relay should be fine. Something like below would cover your logic. I assigned virtual aux 1 to the engine fan function, so you would still set your activation temp and hysteresis etc in the main engine fan settings panel and this will also take care of the speed lockout and engine running lockout. For the DC table, Im not familiar with that relay but you may need to invert these numbers - ie "0%" may be maximum fan speed, not minimum. I would suggest you dont command less than say 15/20%DC in the DC table as most motors will become quite unhappy below that. I would experiment with frequency to see what it likes, start lower, it will likely be ok at 100Hz. Lower frequency will keep the relay cooler. Quote Link to comment Share on other sites More sharing options...
Jens_l Posted June 29 Author Report Share Posted June 29 Thank You Adam! Quote Link to comment Share on other sites More sharing options...
Jens_l Posted July 16 Author Report Share Posted July 16 It works but there is alot of pwm noise from the fan motor. Tried different hz but the sound is always there only different. I can live with the weird sound as long it's not bad for the fan motor. Quote Link to comment Share on other sites More sharing options...
jigga009 Posted July 19 Report Share Posted July 19 On 7/16/2024 at 11:28 AM, Jens_l said: It works but there is alot of pwm noise from the fan motor. Tried different hz but the sound is always there only different. I can live with the weird sound as long it's not bad for the fan motor. The problem you are having is because you are using a solid state relay, not a PWM motor controller. The relay is sending out signals to the fan speed at the same Hz rating you are using in PCLink. You may even have run into the maximum frequency that the solid state relay is able to put out, which is still not fast enough for quiet fan operation. Instead of that Dorman relay, you should be using an actual PWM motor controller. These will take the signal that the G4+ puts out in the Hz range, and then put out their own signal to the fan motors with a frequency in the kHz range, and will give you silent motor operation you are looking for. You then use the same table like you have setup by Adam to control the duty cycle you want the fans to run at. While larger (its larger case is mostly finned heatsink, which I suspect might have something to do with its reliability over the Calsonic Kansai units), the Siemens controller used on the 07-10 Lincoln MKZ, 06-10 Mercury Milan, 07-10 Ford Fusion, 06 Mercury Zephyr and C6 Corvette/Cadillac XLR, and Mercedes SLK and S-class (Mercedes used a slightly differently wired version of the same controller) takes the same PWM-ve signal that Link uses with the G4+, which in turn makes it more intuitive when setting up the PWM tables in the ECU for the fan. The control range of this PWM controller is 10% to 95%. Anything you program outside of these areas will put the controller in failsafe mode and shut the fans off. The other popular choice, the Calsonic Kansai came on 2022+ WRX, 2015 Infiniti Q70, 2017-2019 INFINITI Q6, 09-14 Nissan Juke, 09-14 Nissan GTR, 09-14 Nissan Leaf, 11-13 Mazda 6 3.7l V6, 03-04 Mazda 6, and I'm sure there are a few other applications of the controller. This controller expects a PWM+ve signal, which is an inverted version of what the G4+ puts out (i.e. 90% duty cycle on the ECU is more like 10% fan speed, 80% duty cycle = 20% fan speed, and so on....). With these controllers, you feed them a 500Hz signal from the ECU, and they will put out around 20kHz to the fans. From what I have seen of them though, the Calsonic Kansai units have a lower amp capacity than the Siemens units, and appear to have issues with shedding heat, leading to relatively frequent failures (drawback of the small footprint of these units vs the larger heatsink case of the Siemens unit). In addition, you have the internet forums are littered with stories of failures of these units even when fused at 50A as per OEM killing themselves, often taking harnesses with them in the process. There was a recall for them at one point, so you want to avoid the all-black versions of the controller. Still, there are failures of the "improved" units abound, but the size of the controller is a huge plus for people. With that said, my research indicated that they might be considered almost a "wear item" for many, since they seemed to die every after a couple of years of use. Control range for these Calsonic Kansai controllers is 24%-100% (76% to 0% pwm on the G4+). Anything outside of this range will put the controller in failsafe mode and shut the fans off. This is an important detail for an ECU like the G4+ which uses low side PWM drivers since the PWM signal will be ungrounded when the ECU is off, in essence, giving the controller a signal for 100% fan speed. Also note that when you shut the ECU/Car off, the controller PWM wire will be ungrounded, causing the controller to trigger your fans to run at 100%, as per failsafe mode. To get around this, you would either need to put the PWM wire that runs from the ECU to the controller on a relay that would ground the PWM wire when the car is off. Alternatively, you could just put the controller itself on a relay that shuts it down when the car is shut down. In OEM applications, the Siemens controller is fused at 60A on the C6 Corvette/XLR application. I have the Siemens (Ford Fusion) fan controller fused at 30A for my application, as I use it to run 2 6.5 inch fans together, but the excess amp capacity of the controller means that I don't have to mount it in an airstream in the engine bay to stay cool. Even after about an hour of screwing around with different PWM settings playing with the fans on my G4+ using the Siemens controller with the engine off (and no cooling air running over the controller), the controller is still barely above room temp to the touch. Slight issue with using the Calsonic Kansai controller with the G4+ is that the controller has a failsafe logic requires some inventive wiring on your part so as not to have your fans start running at 100% speed if the PWM signal wire is ungrounded (i.e. when you shut your car/ECU off). There is also the need to invert your PWM table since the G4+ uses low side drivers only. A few around here do use this controller with their G4+ ECU's. It's more work than using the Siemens unit, but it does also appear to be a bit more compact and easier to hide. With that said, the smaller size of the Calsonic Kansai controller also means a lack of cooling capacity, so it's more apt to fail if you are pushing it hard or it is unable to cool itself. The OEMs using this controller seem to manage this issue by mounting the controllers directly behind the radiator fans on the fan shroud so that they were in the direct path of the air pulled in by the fans. You will notice that in the applications where the Siemens controllers are used, they are not mounted in the air stream of the fans. Instead, they are more heavily heatsinked, which I suspect makes them less likely to cook their internals. Again, although physically larger, imo, the Siemens controller is more straight forward an install and setup when using it with the G4+, and it seems to have a higher amp carrying capacity than the Calsonic Kansai unit. If you are getting either of these controllers, do yourself a favour and pick up the associated harness/pigtails that connect to the controllers to make it easier to wire things into your application more seamlessly. As far as sourcing these controllers, eBay is your friend, especially for a good used OEM unit. There are aftermarket PWM controllers available, but I'd stick with OE imo.... dx4picco 1 Quote Link to comment Share on other sites More sharing options...
Laminar Posted July 19 Report Share Posted July 19 I've been running the Siemens setup in my swapped E36 and I nabbed another one for my RX-8: http://www.mikaelvroom.com/wp-content/uploads/2018/05/Photo-May-27-2-26-22-PM-800x600.jpg It'll suck a piece of paper to the radiator from a foot away and it starts softly enough that it doesn't hit the idle. Quote Link to comment Share on other sites More sharing options...
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