Power Window Switch Bad...Anyone Else
Posting Guru
Joined: Jul 2005
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From: San Jose, CA
Front door panel is easy if I remember right. Take out the couple screws on the bottom of the panel, take out the screw from behind the door handle, remove the bolts securing the arm rest, and remove one screw on the forward edge towards the top (if I remember right).
Then the whole thing lifts up and out very easily--Don't try prying anything and end up breaking off a plastic mounting tab like I did :-(
Then the whole thing lifts up and out very easily--Don't try prying anything and end up breaking off a plastic mounting tab like I did :-(
Elder User
Joined: Jan 2008
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The driver door switch gets the most use so it wears out first. The Driver door switch is the master switch which supplies power to the other window switches. If there is no relay the switch contacts themselves have to carry the full current of the power window motor. Power windows do NOT have limit switchs so if you don't take your finger off of the switch the instant the window is fully up or down the motor keeps on trying to move the window until the motor overheats and thermos out to protect itself. Always remove your finger from the switch as soon as the window if fully up or down.
Freshman User
Joined: Aug 2010
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relays?
I have 108000 on my 04 FX4 and replaced this switch assembly twice and did the file fix twice... wonder if relay for drivers window would help this? as it seems to be the one with most use and always looks burnt... ideas? A relay would take the load off the switch itself... just a thought will post more when done...
Posting Guru
Joined: Jul 2005
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From: San Jose, CA
Adding a relay(s) will certainly work. Wiring in an appropriately sized pair of power FETs is probably better since they take up far less space and there will never be anything to burn out.
Rant--Mechanical switch contacts as we have are far cheaper -- $1 saved is $1M/yr saved by Ford assuming they're putting these in 1M trucks every year. Plus, they get to generate parts revenue by selling a bunch of replacement assemblies every time they burn out. Think about it--it only has to work as long as the warranty lasts. We eat the cost afterwards.
Rant--Mechanical switch contacts as we have are far cheaper -- $1 saved is $1M/yr saved by Ford assuming they're putting these in 1M trucks every year. Plus, they get to generate parts revenue by selling a bunch of replacement assemblies every time they burn out. Think about it--it only has to work as long as the warranty lasts. We eat the cost afterwards.
Elder User
Joined: Jan 2008
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Aquaman is right about the way the bean counters work at the auto manufacturers. They really do cut pennies in half. A relay should have been used to carry the high current of the power window motor. Some manufacturers use them while other applications do not. A FET is a good idea too. Short of that always take your finger off of the switch as soon as the window is fully up or down and have the passengers do the same. Don't let the kids sit in the back seat and run the power window up/down up/down when they get bored. As the regulators age the current draw goes up and the load on the switch contacts causes pitting and high resistance. Ouch! Lub the window tracks once in a while helps too. I don't know how the engineers figure this stuff out, but they seem to know how long a part will last and make sure it passes the warranty period. Ford has made millions on the DPFE EGR system, cracked rubber hoses causing P0171 and P0174 and the COPs failing is probably their biggest money maker. On top of that the engineers don't set the misfire DTCs until it gets really bad. Got to love it.
Freshman User
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Fet Schooling anyone?
Ok not knowing enough about FETs and the vast array of applications, these would be the ideal setup for this app, but not sure what FET I would need to do the drivers and pass. windows. Can someone with knowledge of these please point me in the right direction; size to order and wiring of these. Due to the window circut being protected by a 30 amp fuse I presume a 12 volt 30 amp FET would work? Found these on ebay along with many many others MOTOROLA MRFG35010 3.5 GHz 10W 12V POWER FET GaAs RF . Have done some reading and these seem to be very amp and voltage sensitive, but when matched correctly would be the answer to this problem probably for good.
Elder User
Joined: Jan 2008
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You can also use a 30AMP 12Vdc relay.
Pins 85 and 86 are the control(coil) side
Pins 30 and 87 are the LOAD side
When the N.O. contact of the Drivers door window switch is pressed to the CLOSED position power goes to Pin 86(85 is already at ground potential) instead of to the window motor itself. This energizes the relay coil closing N.O. contact 87 of the LOAD side of the relay.
Since Pin 30 already has 12Vdc Pin 87 now puts 12Vdc on the window motor instead of the switch pod doing it directly.
Pins 85 and 86 are the control(coil) side
Pins 30 and 87 are the LOAD side
When the N.O. contact of the Drivers door window switch is pressed to the CLOSED position power goes to Pin 86(85 is already at ground potential) instead of to the window motor itself. This energizes the relay coil closing N.O. contact 87 of the LOAD side of the relay.
Since Pin 30 already has 12Vdc Pin 87 now puts 12Vdc on the window motor instead of the switch pod doing it directly.
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