GMT400 Condenser fan testing

[L31MaxExpress]

I did some testing on the GMT400 condenser pusher fan like the one my 1999 Tahoe came with from GM. I recently added one to the 1987 G20 van. Ended up dropping the vent temps about 5°F at idle as well as reducing some of the stress on the a/c compressor. I have the relay that controls the fan tied into the high blower fan relay turn on signal from the blower motor speed control switch. When I flip the interior blower fan to high speed, it turns on the fan. Later on I will deligate control of the fan to the P59 PCM.

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Here is a clip of the testing. With everything heat soaked, it took about 4-5 minutes for it to provide the lowest presaures and coolest air. That being said the pressures started dropping immediately when I activated it.

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[CumminsFever]

This is interesting! I'm currently driving an '05 vw passat tdi wagon. While it has an engine driven mechanical fan, it also has an electric fan beside the engine driven one. This engine doesn't run hot enough to know if it would come on to assist with engine cooling, but it does run when the a/c is on, and a/c pressures reach a pre-set point. This seems to happen sitting still at idle. It does keep idle a/c cooling very consistent, no noticeable difference in vent temps from idle to cruising.
Of course, at this point I have no gauges, so exact parameters are unknown.
I like the idea of your pusher fan. It's a method that will help the idle/no vehicular movement a/c vent temps.

 

[L31MaxExpress]

This is interesting! I'm currently driving an '05 vw passat tdi wagon. While it has an engine driven mechanical fan, it also has an electric fan beside the engine driven one. This engine doesn't run hot enough to know if it would come on to assist with engine cooling, but it does run when the a/c is on, and a/c pressures reach a pre-set point. This seems to happen sitting still at idle. It does keep idle a/c cooling very consistent, no noticeable difference in vent temps from idle to cruising.
Of course, at this point I have no gauges, so exact parameters are unknown.
I like the idea of your pusher fan. It's a method that will help the idle/no vehicular movement a/c vent temps.

My 2011 Pathfinder has a similar electric puller fan. The mechanical is offset to one side of the radiator, electric to the opposite side and they overlap in the center.

 

[0xDEADBEEF]

My 'burban had one and it never came on. I thought it was bad, but it worked when I put a jumper on the high side sensor (If I remember correctly). My LX470 on the other hand comes on with the AC.

Anyway, I wonder what the duty cycle of that fan is since it appears to only come on in extreme situations.

 

[Wildblue19]

@0xDEADBEEF I run the same fan on my truck. It is triggered by several sensors that feed into a control board I designed, but in the texas heat the way I have it programmed it is on nearly all the time. 2 years like that no issues for me. Just one data point.