New Electric Fan not working
#1
01-27-2019, 08:32 AM
Join Date: Jan 2019
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#3
01-27-2019, 11:07 AM
Legend
Fan should come on with AC compressor or at 210 water temperature. Verify there is a good ground at the motor connection.
The motor wiring is only 10 gauge in a loom with many other wires and connection, which IMO is a size too small in that condition for a 30-40 amp circuit, but I digress (it's only really that high at startup, not sustained). With my Mark8 fan swap, I'm using a 70 amp relay, 60 amp fuse, and 10 gauge stand-alone wiring. It still gets warm (that fan is 80A start 30-40A run)
The motor wiring is only 10 gauge in a loom with many other wires and connection, which IMO is a size too small in that condition for a 30-40 amp circuit, but I digress (it's only really that high at startup, not sustained). With my Mark8 fan swap, I'm using a 70 amp relay, 60 amp fuse, and 10 gauge stand-alone wiring. It still gets warm (that fan is 80A start 30-40A run)
#5
01-27-2019, 11:29 AM
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Short story is mechanic that said it was the fan assembly. I changed it out thinking it was an easy fix. After replacing the fan assembly, Fan relay and coolant sensor. We also jumped the power at the fan relay to get the fan to turn on.( 30 to 87A ) to make sure wires are good from the relay to the fan.
#7
03-20-2019, 09:33 PM
My truck is having the same problem. 04 4.7L 2wd 128k. Replaced electric fan last summer and now new fan won’t come on when A/C is selected. You can feel the temp difference through the vents. I unplugged the ECT sensor and the fan kicked right on.
checked 40a fuse
swapped relays
checked fan connection
made sure compressor is running
jupped fan direct to battery and it runs fine
It’s an Advanced Auto fan btw
I’ll mess with it, then it works, but it doesn’t last and goes down again. It works consistently when unplug the ECT sensor. Banging my head right now.
checked 40a fuse
swapped relays
checked fan connection
made sure compressor is running
jupped fan direct to battery and it runs fine
It’s an Advanced Auto fan btw
I’ll mess with it, then it works, but it doesn’t last and goes down again. It works consistently when unplug the ECT sensor. Banging my head right now.
Last edited by OpieTaylor; 03-20-2019 at 09:40 PM.
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#8
03-20-2019, 10:48 PM
I think I found it, some guy on YouTube says it's not the signal to the compressor that turns the fan on, it's the high pressure sensor on the refrigerant line that actually turns the fan on.
Just unplugged it and cleaned it and fan kicked on, but didn't stay on, so there's something going on and the high pressure switch is not telling fan to run.
Makes since now too, that when I unplugged the ECT sensor it ran, because that was the temp related backup function of the fan with the primary being A/C condenser cooling.
Just unplugged it and cleaned it and fan kicked on, but didn't stay on, so there's something going on and the high pressure switch is not telling fan to run.
Makes since now too, that when I unplugged the ECT sensor it ran, because that was the temp related backup function of the fan with the primary being A/C condenser cooling.
#9
03-21-2019, 01:35 PM
Fan started working again today when the air warmed up.
I'am thinking now, that when the manual says truck needs to be at least 135 degrees and demand from A/C to run the fan, it really means the high pressure side has to be high enough, not just A/C selected on.
Or I have a faulty pressure switch, or a weak compressor, or a low charge, but A/C blows ice cold.
Anyone know if the pressure switch cycles compressor, or the probe in the evaporator?
I'am thinking now, that when the manual says truck needs to be at least 135 degrees and demand from A/C to run the fan, it really means the high pressure side has to be high enough, not just A/C selected on.
Or I have a faulty pressure switch, or a weak compressor, or a low charge, but A/C blows ice cold.
Anyone know if the pressure switch cycles compressor, or the probe in the evaporator?
Last edited by OpieTaylor; 03-21-2019 at 01:39 PM.