I have had e-fans in my 2000 f150 for 3 years now. At first I had 2 from a taurus in stalled.Recently I built a fan shroud and mounted a single fan from a cougar.I also installed a light in my gauge pod so I would know when the fan was on or off. With the dual fan set up the light would start to come on about 75-80. The faster I wemt the brighter the light got.
Since I did the shroud and fan the light comes on around 35. I figure the wind blowing the fan is turning the fan motor into a generator which is lighting up the light. I assume my theory on the light is correct.
Now the problem.With the wind blowing thru the fan and turning it,it can be turning the fan in the wrong direction.Wnen it is time for the fan to come on for the a/c or the temp I think it creates a power spike and blows the fuse due to it running backwards. A blown fuse has only happened a few time but I want to eleminate that fuse blowing problem. I was thinking I need a one way diode to block the power that I think the fan motor is creating.
Can anyone give me any help here as to were to buy this type of diode,what type,what rating? How to install it
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The motors are DC and can generate an electrical output from the air pressure against the fan blades. This happens because there is a magnetic field in the poles the comutator cuts through to generate voltage in reverse.
The fan should revolve in the same direction from air flow as it does by DC power being applied.
It sounds like you have to reverse the power polarity to the motor because it is now actually turning it backwards when powered up.
If this is the case, by "improveing" the air directional capability with another shrould, the motor is turning backwards at a greater rate taking more power to reverse it, and so blows the fuse.
Unless you have a soft start controller; powering a fan this size draws a lot of current without soft start. Your talkng starting currents well over 100 amps for the Taurus and Lincoln fans
They had to be this heffty to be sole cooling on those cars under all conditions.
As for the pilot lamp detecting the fan motor turning from just road speeds, you can install a diode in the lamp lead only, to prevent 'backfeed' from the motor since you should not do anything to keep the fan from turning..
A diode in the fan motor circuit is not the best way to do it because the diode will have some voltage drop and be reguired to be quite large to handle the series current.
Good luck.

 

Wow, you said just what I said. But with a little more uh,education.We are on the same thought page
As for putting a diode in the lamp feed.The lamp feed is in line with the power wire that runs the fan. It seems like the diode would be useless according to what you are saying here,If I understand you correctly.
"As for the pilot lamp detecting the fan motor turning from just road speeds, you can install a diode in the lamp lead only, to prevent 'backfeed' from the motor since you should not do anything to keep the fan from turning..
A diode in the fan motor circuit is not the best way to do it because the diode will have some voltage drop and be reguired to be quite large to handle the series current."